diff --git a/src/formal/divergence_1D_s.F90 b/src/formal/divergence_1D_s.F90
index b7aa0d4..1c12aa1 100644
--- a/src/formal/divergence_1D_s.F90
+++ b/src/formal/divergence_1D_s.F90
@@ -27,6 +27,11 @@ pure function cell_center_locations(x_min, x_max, cells) result(x)
 
 #endif
 
+  ! PURPOSE: Definition of procedure to compute the product of a scalar and a divergence
+  ! KEYWORDS: scalar multiplication
+  ! CONTEXT: Invoke this function via the binary infix operator "*" with scalar and divergence left- and
+  !          right-hand operands, respectively
+
   module procedure premultiply_scalar_1D
     call_julienne_assert(size(scalar_1D%values_) .equalsExpected. size(divergence_1D%values_) + 2)
     scalar_x_divergence_1D%tensor_1D_t = &
@@ -38,18 +43,42 @@ pure function cell_center_locations(x_min, x_max, cells) result(x)
 #endif
     call_julienne_assert(size(scalar_x_divergence_1D%weights_) .equalsExpected. size(divergence_1D%values_)+2)
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to compute the product of a divergence and a scalar
+  ! KEYWORDS: scalar multiplication
+  ! CONTEXT: Invoke this function via the binary infix operator "*" with divergence and scalar left- and
+  !          right-hand operands, respectively
 
   module procedure postmultiply_scalar_1D
     scalar_x_divergence_1D = premultiply_scalar_1D(scalar_1D, divergence_1D) 
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to provide the cell-centered values of divergences.
+  ! KEYWORDS: staggered grid, divergence
+  ! CONTEXT: Invoke this function via the "values" generic binding to produce discrete divergence values.
 
   module procedure divergence_1D_values
     cell_centered_values = self%values_
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to provide staggered-grid locations at which divergence values are stored: cell centers.
+  ! KEYWORDS: cell centers, staggered grid, divergence
+  ! CONTEXT: Invoke this function via the "grid" generic binding to produce discrete gradient-vector locations for
+  !          initialization-function sampling, printing, or plotting.
 
   module procedure divergence_1D_grid
     cell_centers = cell_center_locations(self%x_min_, self%x_max_, self%cells_)
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to compute the quadrature weights for use in the mimetic inner products of a scalar
+  !          and the divergence of a vector.
+  ! KEYWORDS: quadrature, numerical integration, coefficients, weights
+  ! CONTEXT: Invoke this function via the "weights" generic binding to produce the quadrature weights
+  !          associated with mimetic approximations to divergences.
 
   module procedure divergence_1D_weights
       integer c 
@@ -72,5 +101,5 @@ pure function cell_center_locations(x_min, x_max, cells) result(x)
       call_julienne_assert(self%cells_ .isAtLeast. 2*size(skin))
       call_julienne_assert(size(weights) .equalsExpected. self%cells_+2)
   end procedure
-
-end submodule divergence_1D_s
\ No newline at end of file
+  ! END CODE CHUNK
+end submodule divergence_1D_s
diff --git a/src/formal/divergence_operator_1D_s.F90 b/src/formal/divergence_operator_1D_s.F90
index fd0fc18..780b003 100644
--- a/src/formal/divergence_operator_1D_s.F90
+++ b/src/formal/divergence_operator_1D_s.F90
@@ -36,6 +36,10 @@ pure function negate_and_flip(A) result(Ap)
 
 #endif
  
+  ! PURPOSE: Definition of procedure to construct an object representing a 1D mimetic divergence operator.
+  ! KEYWORDS: 1D, divergence operator, sparse matrix, constructor
+  ! CONTEXT: Use this type to assemble a divergence-operator matrix for printing.
+
   module procedure construct_1D_divergence_operator
 
     double precision, allocatable :: Ap(:,:)
@@ -100,6 +104,7 @@ pure function M(k, dx) result(row)
     end function
 
   end procedure construct_1D_divergence_operator
+  ! END CODE CHUNK
 
   module procedure submatrix_A_rows
     call_julienne_assert(allocated(self%upper_))
@@ -186,4 +191,4 @@ pure function e(dir, length) result(unit_vector)
 
   end procedure
 
-end submodule divergence_operator_1D_s
\ No newline at end of file
+end submodule divergence_operator_1D_s
diff --git a/src/formal/gradient_1D_s.F90 b/src/formal/gradient_1D_s.F90
index e3589f1..bbd7f60 100644
--- a/src/formal/gradient_1D_s.F90
+++ b/src/formal/gradient_1D_s.F90
@@ -16,6 +16,12 @@
 
 contains
 
+  ! PURPOSE: Definition of procedure to compute the quadrature weights for use in the mimetic inner products of a vector
+  !          and the gradient of a scalar.
+  ! KEYWORDS: quadrature, numerical integration, coefficients, weights
+  ! CONTEXT: Inovke this function via the "weights" generic binding to produce the quadrature weights
+  !          associated with mimetic approximations to gradients.
+
   module procedure gradient_1D_weights
 
     integer face
@@ -38,6 +44,12 @@
     call_julienne_assert(size(weights) .equalsExpected. self%cells_ + 1)
 
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to compute the scalar (dot) product of a vector and the gradient of a scalar.
+  ! KEYWORDS: scalar product, dot product, inner product
+  ! CONTEXT: Inovke this function via the .dot. binary infix operator in expressions of the form
+  !          g .dot. b with a gradient_1D_t g and a vector_1D_t b.
 
   module procedure dot
     call_julienne_assert(size(gradient_1D%values_) .equalsExpected. size(vector_1D%values_))
@@ -59,5 +71,5 @@
     vector_dot_gradient_1D%weights_ = gradient_1D%gradient_1D_weights()
 #endif
   end procedure
-
+  ! END CODE CHUNK
 end submodule gradient_1D_s
diff --git a/src/formal/gradient_operator_1D_s.F90 b/src/formal/gradient_operator_1D_s.F90
index 0298e58..2c22e39 100644
--- a/src/formal/gradient_operator_1D_s.F90
+++ b/src/formal/gradient_operator_1D_s.F90
@@ -36,7 +36,11 @@ pure function negate_and_flip(A) result(Ap)
   end function
 
 #endif
- 
+
+  ! PURPOSE: Definition of procedure to construct a new mimetic gradient-operator matrix representation of kth order for 1D cells of width dx.
+  ! KEYWORDS: 1D, gradient-operator constructor, sparse matrix
+  ! CONTEXT: Use this function to construct a sparse-matrix represntation of a mimetic gradient operator.
+
   module procedure construct_1D_gradient_operator
 
     call_julienne_assert(cells .isAtLeast. 2*k)
@@ -92,6 +96,7 @@ pure function corbino_castillo_M(k, dx) result(row)
     end function
 
   end procedure construct_1D_gradient_operator
+  ! END CODE CHUNK
 
   module procedure gradient_matrix_multiply
 
@@ -168,4 +173,4 @@ pure function e(dir, length) result(unit_vector)
 
   end procedure
 
-end submodule gradient_operator_1D_s
\ No newline at end of file
+end submodule gradient_operator_1D_s
diff --git a/src/formal/laplacian_s.f90 b/src/formal/laplacian_s.f90
index a8a4eaa..8bfa87e 100644
--- a/src/formal/laplacian_s.f90
+++ b/src/formal/laplacian_s.f90
@@ -5,8 +5,13 @@
   implicit none
 contains
  
+  ! PURPOSE: Definition of procedure to report the number of boundary-adjacent locations at which the Laplacian has reduced-order accuracy.
+  ! KEYWORDS: Laplacian, boundary, order of accuracy
+  ! CONTEXT: Use this function to determine the region of slightly slower convergence for mimetic Laplacian approximations.
+
   module procedure reduced_order_boundary_depth
     num_nodes = self%boundary_depth_
   end procedure
+  ! END CODE CHUNK
 
 end submodule laplacian_s
diff --git a/src/formal/mimetic_operators_1D_m.F90 b/src/formal/mimetic_operators_1D_m.F90
index 22a4670..5241c2b 100644
--- a/src/formal/mimetic_operators_1D_m.F90
+++ b/src/formal/mimetic_operators_1D_m.F90
@@ -36,6 +36,10 @@ pure module function construct_matrix_operator(upper, inner, lower) result(mimet
 
   end interface
 
+  ! PURPOSE: Definition of type to encapsulate a one-dimenstional (1D) mimetic gradient operator matrix.
+  ! KEYWORDS: type definition, 1D gradient operator matrix
+  ! CONTEXT: Use this type to assemble gradient-operator matrix for printing.
+
   type, extends(mimetic_matrix_1D_t) :: gradient_operator_1D_t
     !! Encapsulate a 1D mimetic gradient operator
     private
@@ -48,9 +52,14 @@ pure module function construct_matrix_operator(upper, inner, lower) result(mimet
     generic :: assemble => assemble_gradient
     procedure, non_overridable, private :: assemble_gradient
   end type
+  ! END CODE CHUNK
 
   interface gradient_operator_1D_t
 
+    ! PURPOSE: Interface for procedure to construct a new mimetic gradient-operator matrix representation of kth order for 1D cells of width dx.
+    ! KEYWORDS: 1D, gradient-operator constructor, sparse matrix
+    ! CONTEXT: Use this function to construct a sparse-matrix represntation of a mimetic gradient operator.
+
     pure module function construct_1D_gradient_operator(k, dx, cells) result(gradient_operator_1D)
       !! Construct a mimetic gradient operator
       implicit none
@@ -59,9 +68,14 @@ pure module function construct_1D_gradient_operator(k, dx, cells) result(gradien
       integer, intent(in) :: cells !! number of grid cells
       type(gradient_operator_1D_t) gradient_operator_1D
     end function
+    ! END CODE CHUNK
 
   end interface
 
+  ! PURPOSE: Interface for procedure to encapsulate a 1D mimetic divergence operator matrix.
+  ! KEYWORDS: 1D, divergence operator, sparse matrix
+  ! CONTEXT: Use this type to assemble divergence-operator matrix for printing.
+
   type, extends(mimetic_matrix_1D_t) :: divergence_operator_1D_t
     !! Encapsulate kth-order mimetic divergence operator on m_ cells of width dx
     private
@@ -74,9 +88,14 @@ pure module function construct_1D_gradient_operator(k, dx, cells) result(gradien
     procedure, non_overridable, private :: assemble_divergence
     procedure, non_overridable :: submatrix_A_rows
   end type
+  ! END CODE CHUNK
 
   interface divergence_operator_1D_t
 
+    ! PURPOSE: Interface for procedure to construct an object representing a 1D mimetic divergence operator.
+    ! KEYWORDS: 1D, divergence operator, sparse matrix, constructor
+    ! CONTEXT: Use this type to assemble a divergence-operator matrix for printing.
+
     pure module function construct_1D_divergence_operator(k, dx, cells) result(divergence_operator_1D)
       !! Construct a mimetic gradient operator
       implicit none
@@ -85,6 +104,7 @@ pure module function construct_1D_divergence_operator(k, dx, cells) result(diver
       integer, intent(in) :: cells !! number of grid cells
       type(divergence_operator_1D_t) divergence_operator_1D
     end function
+    ! END CODE CHUNK
 
   end interface
 
diff --git a/src/formal/scalar_1D_s.F90 b/src/formal/scalar_1D_s.F90
index 47fa585..06a9774 100644
--- a/src/formal/scalar_1D_s.F90
+++ b/src/formal/scalar_1D_s.F90
@@ -23,6 +23,12 @@
 
 #ifndef __GFORTRAN__
 
+  ! PURPOSE: Definition of procedure to construct a new scalar_1D_t object by assigning each argument to a corresponding
+  !          corresponding component of the new object.
+  ! KEYWORDS: 1D scalar field constructor
+  ! CONTEXT: Invoke this constructor with a pointer associated with a function to be sampled at a set
+  !          of uniformly-spaced cell centers along one spatial dimension bounded by x_min and x_max.
+
   module procedure construct_1D_scalar_from_function
     call_julienne_assert(x_max .greaterThan. x_min)
     call_julienne_assert(cells .isAtLeast. 2*order)
@@ -32,9 +38,15 @@
     end associate
     scalar_1D%gradient_operator_1D_ = gradient_operator_1D_t(k=order, dx=(x_max - x_min)/cells, cells=cells)
   end procedure
-
+  ! END CODE CHUNK
 #else
 
+  ! PURPOSE: Definition of procedure to construct a new scalar_1D_t object by assigning each argument to a corresponding
+  !          corresponding component of the new object.
+  ! KEYWORDS: 1D scalar field constructor
+  ! CONTEXT: Invoke this constructor with a pointer associated with a function to be sampled at a set
+  !          of uniformly-spaced cell centers along one spatial dimension bounded by x_min and x_max.
+
   pure module function construct_1D_scalar_from_function(initializer, order, cells, x_min, x_max) result(scalar_1D)
     procedure(scalar_1D_initializer_i), pointer :: initializer
     integer, intent(in) :: order !! order of accuracy
@@ -51,6 +63,7 @@ pure module function construct_1D_scalar_from_function(initializer, order, cells
     end associate
     scalar_1D%gradient_operator_1D_ = gradient_operator_1D_t(k=order, dx=(x_max - x_min)/cells, cells=cells)
   end function
+  ! END CODE CHUNK
 
   pure function cell_center_locations(x_min, x_max, cells) result(x)
     double precision, intent(in) :: x_min, x_max
@@ -65,6 +78,10 @@ pure function cell_center_locations(x_min, x_max, cells) result(x)
 
 #endif
 
+  ! PURPOSE: Definition of procedure to compute mimetic approximations to the gradient of scalar fields.
+  ! KEYWORDS: gradient, differential operator
+  ! CONTEXT: Invoke this function via the unary .grad. operator with a right-hand-side, scalar-field operand.
+
   module procedure grad
 
     integer c
@@ -81,6 +98,11 @@ pure function cell_center_locations(x_min, x_max, cells) result(x)
     end associate
 
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to compute mimetic approximations to the Laplacian of a scalar field.
+  ! KEYWORDS: Laplacian, differential operator
+  ! CONTEXT: Invoke this function via the unary .laplacian. operator with a right-hand-side, scalar-field operand.
 
   module procedure laplacian
 
@@ -95,10 +117,16 @@ pure function cell_center_locations(x_min, x_max, cells) result(x)
     end associate
 
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to provide the cell-centered values of scalar quantities.
+  ! KEYWORDS: cell centers, staggered grid, scalar field
+  ! CONTEXT: Invoke this function via the "values" generic binding to produce discrete scalar values.
 
   module procedure scalar_1D_values
     cell_centers_extended_values = self%values_
   end procedure
+  ! END CODE CHUNK
 
   pure function scalar_1D_grid_locations(x_min, x_max, cells) result(x)
     double precision, intent(in) :: x_min, x_max
@@ -111,8 +139,14 @@ pure function scalar_1D_grid_locations(x_min, x_max, cells) result(x)
     end associate
   end function
 
+  ! PURPOSE: Definition of procedure to provide the staggered-grid locations at which scalar values are stored: cell centers plus domain boundaries.
+  ! KEYWORDS: staggered grid, scalar field, cell centers
+  ! CONTEXT: Invoke this function via the "grid" generic binding to produce discrete scalar locations for
+  !          initialization-function sampling, printing, or plotting.
+
   module procedure scalar_1D_grid
     cell_centers_extended  = scalar_1D_grid_locations(self%x_min_, self%x_max_, self%cells_)
   end procedure
+  ! END CODE CHUNK
 
-end submodule scalar_1D_s
\ No newline at end of file
+end submodule scalar_1D_s
diff --git a/src/formal/scalar_x_divergence_1D_s.F90 b/src/formal/scalar_x_divergence_1D_s.F90
index 93b9b04..1d3ea8d 100644
--- a/src/formal/scalar_x_divergence_1D_s.F90
+++ b/src/formal/scalar_x_divergence_1D_s.F90
@@ -9,9 +9,15 @@
 
 contains
 
+  ! PURPOSE: Definition of procedure to perform mimetic volume integration of a scalar/divergence dot product.
+  ! KEYWORDS: triple integral, volume integral
+  ! CONTEXT: Invoke this function in expressions of the form  .SSS. (f * .div. v) * dV
+  !          with a vector_1D_t v, a scalar f, and a differential volume dV.
+
   module procedure volume_integrate_scalar_x_divergence_1D
     call_julienne_assert(size(integrand%weights_ ) .equalsExpected. size(integrand%values_)+2)
     integral  = sum(integrand%weights_ * [0D0, integrand%values_, 0D0])
   end procedure
+  ! END CODE CHUNK
 
 end submodule scalar_x_divergence_1D_s
diff --git a/src/formal/tensor_1D_s.f90 b/src/formal/tensor_1D_s.f90
index c67558b..f7a6f09 100644
--- a/src/formal/tensor_1D_s.f90
+++ b/src/formal/tensor_1D_s.f90
@@ -5,6 +5,11 @@
   implicit none
 contains
 
+  ! PURPOSE: Definition of procedure to construct a new tensor_1D_t object by assigning each argument to a corresponding
+  !          corresponding component of the new object.
+  ! KEYWORDS: 1D tensor constructor
+  ! CONTEXT: Constructors for child types assign this function's result to to the child object's parent component.
+
   module procedure construct_1D_tensor_from_components
     tensor_1D%values_ = values
     tensor_1D%x_min_  = x_min
@@ -12,10 +17,15 @@
     tensor_1D%cells_  = cells 
     tensor_1D%order_  = order
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to provide a uniform cell width along the x-coordinate spatial direction.
+  ! KEYWORDS: abcissa, mesh spacing
+  ! CONTEXT: Use this function to produce cell widths for uniform 1D meshes.
 
   module procedure dx
     dx = (self%x_max_ - self%x_min_)/self%cells_
   end procedure
-
+  ! END CODE CHUNK
 
 end submodule tensor_1D_s
diff --git a/src/formal/tensors_1D_m.F90 b/src/formal/tensors_1D_m.F90
index 2615a7c..3c817d1 100644
--- a/src/formal/tensors_1D_m.F90
+++ b/src/formal/tensors_1D_m.F90
@@ -24,12 +24,27 @@ module tensors_1D_m
 
   abstract interface
 
+    ! PURPOSE: Interface for procedure to provide values for initializing a scalar_1D_t object at the cell centers and boundaries
+    !          for use in the mimetic discretization scheme of Corbino-Castillo (2020)
+    ! KEYWORDS: mimetic discretization, scalar function, sampling, one-dimensional (1D)
+    ! CONTEXT: This abstract interface is used to declare a procedure pointer that can be associated with
+    !          a user-defined function.  The user's function can be invoked via this abstract interface
+    !          to sample the function at the appropriate grid locations.
+
     pure function scalar_1D_initializer_i(x) result(f)
       !! Sampling function for initializing a scalar_1D_t object
       implicit none
       double precision, intent(in) :: x(:)
       double precision, allocatable :: f(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide values for initializing a vector function of one spatial dimension at cell faces
+    !          as defined in the mimetic discretization scheme of Corbino-Castillo (2020).
+    ! KEYWORDS: mimetic discretization, vector function, sampling,  1D
+    ! CONTEXT: This abstract interface is used to declare a procedure pointer that can be associated with
+    !          a user-defined function.  The user's function can be invoked via this abstract interface
+    !          to sample the function at the appropriate grid locations.
 
     pure function vector_1D_initializer_i(x) result(v)
       !! Sampling function for initializing a vector_1D_t object
@@ -37,9 +52,15 @@ pure function vector_1D_initializer_i(x) result(v)
       double precision, intent(in) :: x(:)
       double precision, allocatable :: v(:)
     end function
+    ! END CODE CHUNK
 
   end interface
 
+  ! PURPOSE: Definition for type to encapsulate the data and operations that are common to most or all tensor_1D_t child types
+  ! KEYWORDS: type definition, mimetic discretization, grid values, grid functions, 1D
+  ! CONTEXT: Child types extend this derived type to define specific types of tensors such as scalars,
+  !          vectors, gradients, and divergences.
+
   type tensor_1D_t
     !! Encapsulate the components that are common to all 1D tensors.
     !! Child types define the operations supported by each child, including
@@ -56,9 +77,15 @@ pure function vector_1D_initializer_i(x) result(v)
     generic :: dV => dx
     procedure, non_overridable :: dx
   end type
+  ! END CODE CHUNK
 
   interface tensor_1D_t
 
+    ! PURPOSE: Interface for procedure to construct a new tensor_1D_t object by assigning each argument to a corresponding
+    !          corresponding component of the new object.
+    ! KEYWORDS: 1D tensor constructor
+    ! CONTEXT: Constructors for child types assign this function's result to to the child object's parent component.
+
     pure module function construct_1D_tensor_from_components(values, x_min, x_max, cells, order) result(tensor_1D)
       !! User-defined constructor: result is a 1D tensor defined by assigning the dummy arguments to corresponding components
       implicit none
@@ -69,9 +96,14 @@ pure module function construct_1D_tensor_from_components(values, x_min, x_max, c
       integer,          intent(in) :: order     !! order of accuracy
       type(tensor_1D_t) tensor_1D
     end function
+    ! END CODE CHUNK
 
   end interface
 
+  ! PURPOSE: Definition for type to encapsulate a scalar function of one spatial dimension as a tensor with a gradient operator.
+  ! KEYWORDS: type definition, 1D scalar field abstraction
+  ! CONTEXT: Combine with other tensors via expressions that may include differential operators
+
   type, extends(tensor_1D_t) :: scalar_1D_t
     !! Encapsulate scalar values at cell centers and boundaries
     private
@@ -86,9 +118,16 @@ pure module function construct_1D_tensor_from_components(values, x_min, x_max, c
     procedure, non_overridable, private :: scalar_1D_values
     procedure, non_overridable, private :: scalar_1D_grid
   end type
+  ! END CODE CHUNK
 
   interface scalar_1D_t
 
+    ! PURPOSE: Interface for procedure to construct a new scalar_1D_t object by assigning each argument to a corresponding
+    !          corresponding component of the new object.
+    ! KEYWORDS: 1D scalar field constructor
+    ! CONTEXT: Invoke this constructor with a pointer associated with a function to be sampled at a set
+    !          of uniformly-spaced cell centers along one spatial dimension bounded by x_min and x_max.
+
     pure module function construct_1D_scalar_from_function(initializer, order, cells, x_min, x_max) result(scalar_1D)
       !! Result is a collection of cell-centered-extended values with a corresponding mimetic gradient operator
       implicit none
@@ -99,9 +138,14 @@ pure module function construct_1D_scalar_from_function(initializer, order, cells
       double precision, intent(in) :: x_max !! grid location maximum
       type(scalar_1D_t) scalar_1D
     end function
+    ! END CODE CHUNK
 
   end interface
 
+  ! PURPOSE: Definition for type to encapsulate a vector function of one spatial dimension as a tensor with a divergence operator.
+  ! KEYWORDS: type definition, 1D vector field abstraction
+  ! CONTEXT: Combine with other tensors via expressions that may include differential operators
+
   type, extends(tensor_1D_t) :: vector_1D_t
     !! Encapsulate 1D vector values at cell faces (of unit area for 1D) and corresponding operators
     private
@@ -122,15 +166,26 @@ pure module function construct_1D_scalar_from_function(initializer, order, cells
     procedure, non_overridable, private :: vector_1D_grid
     procedure, non_overridable, private :: vector_1D_values
   end type
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of type to encapsulate a scalar/vector product weighted for integration on a surface
+  ! KEYWORDS: type definition, 1D product abstraction
+  ! CONTEXT: Combine with other tensors via expressions that may include the double integrals
 
   type, extends(tensor_1D_t) :: weighted_product_1D_t
   contains
     generic :: operator(.SS.) => surface_integrate_vector_x_scalar_1D
     procedure, non_overridable, private :: surface_integrate_vector_x_scalar_1D
   end type
+  ! END CODE CHUNK
 
   interface vector_1D_t
 
+    ! PURPOSE: Interface for procedure to construct a new vector_1D_t object by sampling a function of one spatial dimension.
+    ! KEYWORDS: 1D vector field constructor
+    ! CONTEXT: Invoke this constructor with a pointer associated with a function to be sampled at a set
+    !          of uniformly-spaced cell faces along one spatial dimension bounded by x_min and x_max.
+
     pure module function construct_1D_vector_from_function(initializer, order, cells, x_min, x_max) result(vector_1D)
       !! Result is a 1D vector with values initialized by the provided procedure pointer sampled on the specified
       !! number of evenly spaced cells covering [x_min, x_max]
@@ -142,16 +197,27 @@ pure module function construct_1D_vector_from_function(initializer, order, cells
       double precision, intent(in) :: x_max !! grid location maximum
       type(vector_1D_t) vector_1D
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to construct a new vector_1D_t object from a parent tensor and a divergence operator object.
+    ! KEYWORDS: 1D vector field constructor
+    ! CONTEXT: Invoke this constructor with a an object to be used to define the constructed parent component
+    !          divergence-operator matrix component.
 
     pure module function construct_from_components(tensor_1D, divergence_operator_1D) result(vector_1D)
-      !! Result is a 1D vector with the provided parent component tensor_1D and the provided divergence operatror
+      !! Result is a 1D vector with the provided parent component tensor_1D and the provided divergence operator
       type(tensor_1D_t), intent(in) :: tensor_1D
       type(divergence_operator_1D_t), intent(in) :: divergence_operator_1D
       type(vector_1D_t) vector_1D
     end function
+    ! END CODE CHUNK
 
   end interface
 
+  ! PURPOSE: Definition of type for a vector child type for capturing gradient data and a scalar (dot) product operator.
+  ! KEYWORDS: type definition, 1D gradient vector field abstraction
+  ! CONTEXT: The scalar_1D_t .grad. operator produces this type as a result.
+
   type, extends(vector_1D_t) :: gradient_1D_t
     !! A 1D mimetic gradient vector field abstraction with a public method that produces corresponding numerical quadrature weights
   contains
@@ -161,6 +227,11 @@ pure module function construct_from_components(tensor_1D, divergence_operator_1D
 #endif
     procedure, non_overridable, private, pass(gradient_1D) :: dot
   end type
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of type for a tensor child type for capturing the scalar (dot) product of a vector and a gradient vector data
+  ! KEYWORDS: type definition, 1D vector/gradient scalar product
+  ! CONTEXT: An instance of this type can serve as an integrand in a .SSS. triple-integral operator.
 
   type, extends(tensor_1D_t) :: vector_dot_gradient_1D_t
     !! Result is the dot product of a 1D vector field and a 1D gradient field
@@ -170,6 +241,12 @@ pure module function construct_from_components(tensor_1D, divergence_operator_1D
     generic :: operator(.SSS.) => volume_integrate_vector_dot_grad_scalar_1D
     procedure, non_overridable, private, pass(integrand) ::volume_integrate_vector_dot_grad_scalar_1D
   end type
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of type for a tensor child type capturing the divergence of a vector function of one spatial dimension.
+  ! KEYWORDS: type definition, 1D, divergence
+  ! CONTEXT: Although a mathematical scalar, this type differs from scalar_1D_t in that the values are stored
+  !          _only_ at cell centers, whereas a scalar_1D_t object additionally has values at domain boundaries.
 
   type, extends(tensor_1D_t) :: divergence_1D_t
     !! Encapsulate divergences at cell centers
@@ -183,6 +260,11 @@ pure module function construct_from_components(tensor_1D, divergence_operator_1D
     procedure, non_overridable, private :: divergence_1D_values
     procedure, non_overridable, private :: divergence_1D_grid
   end type
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of type for a tensor child type for capturing the product of a scalar and divergence
+  ! KEYWORDS: type definition, 1D scalar/divergence product
+  ! CONTEXT: An instance of this type can serve as an integrand in a .SSS. triple-integral operator.
 
   type, extends(tensor_1D_t) :: scalar_x_divergence_1D_t
     !! product of a 1D scalar field and a 1D divergence field
@@ -192,6 +274,13 @@ pure module function construct_from_components(tensor_1D, divergence_operator_1D
     generic :: operator(.SSS.) => volume_integrate_scalar_x_divergence_1D
     procedure, non_overridable, private, pass(integrand) :: volume_integrate_scalar_x_divergence_1D
   end type
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of type for a divergence child type capturing the result of applying a divergence operator to a gradient.
+  ! KEYWORDS: type definition, 1D, laplacian
+  ! CONTEXT: Although a mathematical a divergence, this type additionally provides a type-bound procedure that
+  !          returns the number of boundary-adjacent points at which the Laplacian approximation's accuracy drops by
+  !          by one order relative to the parent divergence type.
 
   type, extends(divergence_1D_t) :: laplacian_1D_t
     private
@@ -199,9 +288,14 @@ pure module function construct_from_components(tensor_1D, divergence_operator_1D
   contains
     procedure reduced_order_boundary_depth
   end type
+  ! END CODE CHUNK
 
   interface
 
+    ! PURPOSE: Interface for procedure to provide the differential area for use in surface integrals.
+    ! KEYWORDS: surface integral, area integral, double integral, numerical quadrature, mimetic discretization
+    ! CONTEXT: Use this in expressions of the form .SS. (f .x. (v .dot. dA)) with a scalar_1D_t f and vector_1D_t v
+
     pure module function dA(self)
       !! Result is the grid's discrete surface-area differential for use in surface integrals of the form
       !! .SS. (f .x. (v .dot. dA))
@@ -209,6 +303,11 @@ pure module function dA(self)
       class(vector_1D_t), intent(in) :: self
       double precision dA
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide a uniform cell width along the x-coordinate spatial direction.
+    ! KEYWORDS: abcissa, mesh spacing
+    ! CONTEXT: Use this function to produce cell widths for uniform 1D meshes.
 
     pure module function dx(self)
       !! Result is the uniform cell width
@@ -216,13 +315,25 @@ pure module function dx(self)
       class(tensor_1D_t), intent(in) :: self
       double precision dx
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide the staggered-grid locations at which scalar values are stored: cell centers plus domain boundaries.
+    ! KEYWORDS: staggered grid, scalar field, cell centers
+    ! CONTEXT: Invoke this function via the "grid" generic binding to produce discrete scalar locations for
+    !          initialization-function sampling, printing, or plotting.
 
     pure module function scalar_1D_grid(self) result(cell_centers_extended)
-      !! Result is the array of locations at which 1D scalars are defined: cell centers agumented by spatial boundaries
+      !! Result is the array of locations at which 1D scalars are defined: cell centers augmented by spatial boundaries
       implicit none
       class(scalar_1D_t), intent(in) :: self
       double precision, allocatable :: cell_centers_extended(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide staggered-grid locations at which vector values are stored: cell faces.
+    ! KEYWORDS: abcissa, cell faces
+    ! CONTEXT: Invoke this function via the "grid" generic binding to produce discrete vector locations for
+    !          initialization-function sampling, printing, or plotting.
 
     pure module function vector_1D_grid(self) result(cell_faces)
       !! Result is the array of cell face locations (of unit area for 1D) at which 1D vectors are defined
@@ -230,6 +341,12 @@ pure module function vector_1D_grid(self) result(cell_faces)
       class(vector_1D_t), intent(in) :: self
       double precision, allocatable :: cell_faces(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide staggered-grid locations at which divergence values are stored: cell centers.
+    ! KEYWORDS: cell centers, staggered grid, divergence
+    ! CONTEXT: Invoke this function via the "grid" generic binding to produce discrete gradient-vector locations for
+    !          initialization-function sampling, printing, or plotting.
 
     pure module function divergence_1D_grid(self) result(cell_centers)
       !! Result is the array of cell centers at which 1D divergences are defined
@@ -237,6 +354,11 @@ pure module function divergence_1D_grid(self) result(cell_centers)
       class(divergence_1D_t), intent(in) :: self
       double precision, allocatable :: cell_centers(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide the cell-centered values of scalar quantities.
+    ! KEYWORDS: cell centers, staggered grid, scalar field
+    ! CONTEXT: Invoke this function via the "values" generic binding to produce discrete scalar values.
 
     pure module function scalar_1D_values(self) result(cell_centers_extended_values)
       !! Result is an array of 1D scalar values at boundaries and cell centers
@@ -244,6 +366,11 @@ pure module function scalar_1D_values(self) result(cell_centers_extended_values)
       class(scalar_1D_t), intent(in) :: self
       double precision, allocatable :: cell_centers_extended_values(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide the cell face-centered values of vector quantities.
+    ! KEYWORDS: staggered grid, vector field
+    ! CONTEXT: Invoke this function via the "values" generic binding to produce discrete vector values.
 
     pure module function vector_1D_values(self) result(face_centered_values)
       !! Result is an array of the 1D vector values at cell faces (of unit area 1D)
@@ -251,6 +378,11 @@ pure module function vector_1D_values(self) result(face_centered_values)
       class(vector_1D_t), intent(in) :: self
       double precision, allocatable :: face_centered_values(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to provide the cell-centered values of divergences.
+    ! KEYWORDS: staggered grid, divergence
+    ! CONTEXT: Invoke this function via the "values" generic binding to produce discrete divergence values.
 
     pure module function divergence_1D_values(self) result(cell_centered_values)
       !! Result is an array of 1D divergences at cell centers
@@ -258,6 +390,11 @@ pure module function divergence_1D_values(self) result(cell_centered_values)
       class(divergence_1D_t), intent(in) :: self
       double precision, allocatable :: cell_centered_values(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute mimetic approximations to the gradient of scalar fields.
+    ! KEYWORDS: gradient, differential operator
+    ! CONTEXT: Invoke this function via the unary .grad. operator with a right-hand-side, scalar-field operand.
 
     pure module function grad(self) result(gradient_1D)
       !! Result is mimetic gradient of the scalar_1D_t "self"
@@ -265,6 +402,11 @@ pure module function grad(self) result(gradient_1D)
       class(scalar_1D_t), intent(in) :: self
       type(gradient_1D_t) gradient_1D
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute mimetic approximations to the Laplacian of a scalar field.
+    ! KEYWORDS: Laplacian, differential operator
+    ! CONTEXT: Invoke this function via the unary .laplacian. operator with a right-hand-side, scalar-field operand.
 
     pure module function laplacian(self) result(laplacian_1D)
       !! Result is mimetic Laplacian of the scalar_1D_t "self"
@@ -272,6 +414,11 @@ pure module function laplacian(self) result(laplacian_1D)
       class(scalar_1D_t), intent(in) :: self
       type(laplacian_1D_t) laplacian_1D
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to report the number of boundary-adjacent locations at which the Laplacian has reduced-order accuracy.
+    ! KEYWORDS: Laplacian, boundary, order of accuracy
+    ! CONTEXT: Use this function to determine the region of slightly slower convergence for mimetic Laplacian approximations.
 
     pure module function reduced_order_boundary_depth(self) result(num_nodes)
       !! Result is number of nodes away from the boundary for which convergence rate is one degree lower
@@ -279,6 +426,11 @@ pure module function reduced_order_boundary_depth(self) result(num_nodes)
       class(laplacian_1D_t), intent(in) :: self
       integer num_nodes
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute mimetic approximations to the divergence of a vector field.
+    ! KEYWORDS: divergence, vector field
+    ! CONTEXT: Invoke this function via the unary .div. operator with a right-hand-side vector-field operand.
 
     pure module function div(self) result(divergence_1D)
       !! Result is mimetic divergence of the vector_1D_t "self"
@@ -286,6 +438,12 @@ pure module function div(self) result(divergence_1D)
       class(vector_1D_t), intent(in) :: self
       type(divergence_1D_t) divergence_1D !! discrete divergence
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to perform mimetic volume integration of a vector/scalar-gradient dot product.
+    ! KEYWORDS: triple integral, volume integral
+    ! CONTEXT: Invoke this function in expressions of the form .SSS. (v .dot. .grad. f) * dV
+    !          with a vector_1D_t v, a scalar f, and a differential volume dV.
 
     pure module function volume_integrate_vector_dot_grad_scalar_1D(integrand) result(integral)
       !! Result is the mimetic quadrature corresponding to a volume integral of a vector-gradient dot product
@@ -293,6 +451,12 @@ pure module function volume_integrate_vector_dot_grad_scalar_1D(integrand) resul
       class(vector_dot_gradient_1D_t), intent(in) :: integrand
       double precision integral
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to perform mimetic volume integration of a scalar/divergence dot product.
+    ! KEYWORDS: triple integral, volume integral
+    ! CONTEXT: Invoke this function in expressions of the form  .SSS. (f * .div. v) * dV
+    !          with a vector_1D_t v, a scalar f, and a differential volume dV.
 
     pure module function volume_integrate_scalar_x_divergence_1D(integrand) result(integral)
       !! Result is the mimetic quadrature corresponding to a volume integral of a scalar-divergence product
@@ -300,13 +464,25 @@ pure module function volume_integrate_scalar_x_divergence_1D(integrand) result(i
       class(scalar_x_divergence_1D_t), intent(in) :: integrand
       double precision integral
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to perform mimetic surface integration of a scalar/vector product.
+    ! KEYWORDS: double integral, surface integral, flux
+    ! CONTEXT: Invoke this function in expressions of the form -.SS. (f .x. (v .dot. dA))
+    !          with a vector_1D_t v, a scalar_1D_t f, and a differential area dA.
 
     pure module function surface_integrate_vector_x_scalar_1D(integrand) result(integral)
-      !! Result is the mimetic quadrature correspondingto a surface integral of a scalar-vector product
+      !! Result is the mimetic quadrature corresponding to a surface integral of a scalar-vector product
       implicit none
       class(weighted_product_1D_t), intent(in) :: integrand
       double precision integral
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute the scalar (dot) product of a vector and the gradient of a scalar.
+    ! KEYWORDS: scalar product, dot product, inner product
+    ! CONTEXT: Inovke this function via the .dot. binary infix operator in expressions of the form
+    !          g .dot. b with a gradient_1D_t g and a vector_1D_t b.
 
     pure module function dot(vector_1D, gradient_1D) result(vector_dot_gradient_1D)
       !! Result is the mimetic divergence of the vector_1D_t "self"
@@ -315,6 +491,12 @@ pure module function dot(vector_1D, gradient_1D) result(vector_dot_gradient_1D)
       type(vector_1D_t), intent(in) :: vector_1D
       type(vector_dot_gradient_1D_t) vector_dot_gradient_1D
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute the scalar (not) product of a vector and a differential area.
+    ! KEYWORDS: dot product, flux, surface-normal
+    ! CONTEXT: Inovke this function via the .dot. binary infix operator in expressions of the form
+    !          .SS. (f .x. (v .dot. dA)) with a saclar_1D_t f, a vector_1D_t v, and a differential area A.
 
     pure module function dot_surface_normal(vector_1D, dS) result(v_dot_dS)
       !! Result is magnitude of a vector/surface-normal dot product for use in surface integrals of the form
@@ -325,6 +507,12 @@ pure module function dot_surface_normal(vector_1D, dS) result(v_dot_dS)
       double precision, intent(in) :: dS
       type(vector_1D_t) v_dot_dS
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute a scalar/vector product weighted for subsequent surface integration.
+    ! KEYWORDS: integrand, surface integral, double integral
+    ! CONTEXT: Inovke this function .x. binary infix operator in expressions of the form
+    !          .SS. (f .x. (v .dot. dA)) with a saclar_1D_t f, a vector_1D_t v, and a differential area A.
 
     pure module function weighted_premultiply(scalar_1D, vector_1D) result(weighted_product_1D)
       !! Result is the product of a boundary-weighted vector_1D_t with a scalar_1D_t
@@ -333,6 +521,13 @@ pure module function weighted_premultiply(scalar_1D, vector_1D) result(weighted_
       class(vector_1D_t), intent(in) :: vector_1D
       type(weighted_product_1D_t) weighted_product_1D
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute the quadrature weights for use in the mimetic inner products of a vector
+    !          and the gradient of a scalar.
+    ! KEYWORDS: quadrature, numerical integration, coefficients, weights
+    ! CONTEXT: Inovke this function via the "weights" generic binding to produce the quadrature weights
+    !          associated with mimetic approximations to gradients.
 
     pure module function gradient_1D_weights(self) result(weights)
       !! Result is an array of quadrature coefficients that can be used to compute a weighted
@@ -341,14 +536,27 @@ pure module function gradient_1D_weights(self) result(weights)
       class(tensor_1D_t), intent(in) :: self
       double precision, allocatable :: weights(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute the quadrature weights for use in the mimetic inner products of a scalar
+    !          and the divergence of a vector.
+    ! KEYWORDS: quadrature, numerical integration, coefficients, weights
+    ! CONTEXT: Invoke this function via the "weights" generic binding to produce the quadrature weights
+    !          associated with mimetic approximations to divergences.
 
     pure module function divergence_1D_weights(self) result(weights)
       !! Result is an array of quadrature coefficients that can be used to compute a weighted
-      !! inner product  of a vector_1D_t object and a gradient_1D_t object.
+      !! inner product  of a scalar_1D_t object and a divergence_1D_t object.
       implicit none
       class(tensor_1D_t), intent(in) :: self
       double precision, allocatable :: weights(:)
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute the product of a scalar and a divergence
+    ! KEYWORDS: scalar multiplication
+    ! CONTEXT: Invoke this function via the binary infix operator "*" with scalar and divergence left- and
+    !          right-hand operands, respectively
 
     pure module function premultiply_scalar_1D(scalar_1D, divergence_1D) result(scalar_x_divergence_1D)
       !! Result is the point-wise product of a 1D scalar field and the divergence of a 1D vector field
@@ -357,6 +565,12 @@ pure module function premultiply_scalar_1D(scalar_1D, divergence_1D) result(scal
       class(divergence_1D_t), intent(in) :: divergence_1D
       type(scalar_x_divergence_1D_t) scalar_x_divergence_1D
     end function
+    ! END CODE CHUNK
+
+    ! PURPOSE: Interface for procedure to compute the product of a divergence and a scalar
+    ! KEYWORDS: scalar multiplication
+    ! CONTEXT: Invoke this function via the binary infix operator "*" with divergence and scalar left- and
+    !          right-hand operands, respectively
 
     pure module function postmultiply_scalar_1D(divergence_1D, scalar_1D) result(scalar_x_divergence_1D)
       !! Result is the point-wise product of a 1D scalar field and the divergence of a 1D vector field
@@ -365,6 +579,7 @@ pure module function postmultiply_scalar_1D(divergence_1D, scalar_1D) result(sca
       type(scalar_1D_t), intent(in) :: scalar_1D
       type(scalar_x_divergence_1D_t) scalar_x_divergence_1D
     end function
+    ! END CODE CHUNK
 
   end interface
 
diff --git a/src/formal/vector_1D_s.F90 b/src/formal/vector_1D_s.F90
index 6410b31..65bbf25 100644
--- a/src/formal/vector_1D_s.F90
+++ b/src/formal/vector_1D_s.F90
@@ -22,13 +22,24 @@
 
 contains
 
+  ! PURPOSE: Definition of procedure to compute the scalar (not) product of a vector and a differential area.
+  ! KEYWORDS: dot product, flux, surface-normal
+  ! CONTEXT: Inovke this function via the .dot. binary infix operator in expressions of the form
+  !          .SS. (f .x. (v .dot. dA)) with a saclar_1D_t f, a vector_1D_t v, and a differential area A.
+
   module procedure dot_surface_normal
      v_dot_dS%tensor_1D_t = tensor_1D_t(vector_1D%values_*dS, vector_1D%x_min_, vector_1D%x_max_, vector_1D%cells_, vector_1D%order_)
      v_dot_dS%divergence_operator_1D_ = vector_1D%divergence_operator_1D_
   end procedure
+  ! END CODE CHUNK
 
 #ifndef __GFORTRAN__
 
+  ! PURPOSE: Definition of procedure to construct a new vector_1D_t object by sampling a function of one spatial dimension.
+  ! KEYWORDS: 1D vector field constructor
+  ! CONTEXT: Invoke this constructor with a pointer associated with a function to be sampled at a set
+  !          of uniformly-spaced cell faces along one spatial dimension bounded by x_min and x_max.
+
   module procedure construct_1D_vector_from_function
     call_julienne_assert(x_max .greaterThan. x_min)
     call_julienne_assert(cells .isAtLeast. 2*order+1)
@@ -38,9 +49,15 @@
     end associate
     vector_1D%divergence_operator_1D_ = divergence_operator_1D_t(k=order, dx=(x_max - x_min)/cells, cells=cells)
   end procedure
+  ! END CODE CHUNK
 
 #else
 
+  ! PURPOSE: Definition of procedure to construct a new vector_1D_t object by sampling a function of one spatial dimension.
+  ! KEYWORDS: 1D vector field constructor
+  ! CONTEXT: Invoke this constructor with a pointer associated with a function to be sampled at a set
+  !          of uniformly-spaced cell faces along one spatial dimension bounded by x_min and x_max.
+
   pure module function construct_1D_vector_from_function(initializer, order, cells, x_min, x_max) result(vector_1D)
     procedure(vector_1D_initializer_i), pointer :: initializer
     integer, intent(in) :: order !! order of accuracy
@@ -57,13 +74,24 @@ pure module function construct_1D_vector_from_function(initializer, order, cells
     end associate
     vector_1D%divergence_operator_1D_ = divergence_operator_1D_t(k=order, dx=(x_max - x_min)/cells, cells=cells)
   end function
+  ! END CODE CHUNK
 
 #endif
 
+  ! PURPOSE: Definition of procedure to construct a new vector_1D_t object from a parent tensor and a divergence operator object.
+  ! KEYWORDS: 1D vector field constructor
+  ! CONTEXT: Invoke this constructor with a an object to be used to define the constructed parent component
+  !          divergence-operator matrix component.
+
   module procedure construct_from_components
     vector_1D%tensor_1D_t = tensor_1D
     vector_1D%divergence_operator_1D_ = divergence_operator_1D
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to compute mimetic approximations to the divergence of a vector field.
+  ! KEYWORDS: divergence, vector field
+  ! CONTEXT: Invoke this function via the unary .div. operator with a right-hand-side vector-field operand.
 
   module procedure div
 
@@ -89,10 +117,16 @@ pure module function construct_1D_vector_from_function(initializer, order, cells
     end associate
 
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to provide the cell face-centered values of vector quantities.
+  ! KEYWORDS: staggered grid, vector field
+  ! CONTEXT: Invoke this function via the "values" generic binding to produce discrete vector values.
 
   module procedure vector_1D_values
     face_centered_values = self%values_
   end procedure
+  ! END CODE CHUNK
 
   pure function faces(x_min, x_max, cells) result(x)
     double precision, intent(in) :: x_min, x_max
@@ -105,9 +139,20 @@ pure function faces(x_min, x_max, cells) result(x)
     end associate
   end function
 
+  ! PURPOSE: Definition of procedure to provide staggered-grid locations at which vector values are stored: cell faces.
+  ! KEYWORDS: abcissa, cell faces
+  ! CONTEXT: Invoke this function via the "grid" generic binding to produce discrete vector locations for
+  !          initialization-function sampling, printing, or plotting.
+
   module procedure vector_1D_grid
     cell_faces  = faces(self%x_min_, self%x_max_, self%cells_)
   end procedure
+  ! END CODE CHUNK
+
+  ! PURPOSE: Definition of procedure to compute a scalar/vector product weighted for subsequent surface integration.
+  ! KEYWORDS: integrand, surface integral, double integral
+  ! CONTEXT: Inovke this function .x. binary infix operator in expressions of the form
+  !          .SS. (f .x. (v .dot. dA)) with a saclar_1D_t f, a vector_1D_t v, and a differential area A.
 
   module procedure weighted_premultiply
 
@@ -190,8 +235,12 @@ pure function postmultiply_diagonal(A,d) result(AD)
 
   end procedure
 
+  ! PURPOSE: Definition of procedure to provide the differential area for use in surface integrals.
+  ! KEYWORDS: surface integral, area integral, double integral, numerical quadrature, mimetic discretization
+  ! CONTEXT: Use this in expressions of the form .SS. (f .x. (v .dot. dA)) with a scalar_1D_t f and vector_1D_t v
   module procedure dA
     dA = 1D0
   end procedure
+  ! END CODE CHUNK
 
-end submodule vector_1D_s
\ No newline at end of file
+end submodule vector_1D_s
diff --git a/src/formal/vector_dot_gradient_1D_s.F90 b/src/formal/vector_dot_gradient_1D_s.F90
index f91e460..93a4149 100644
--- a/src/formal/vector_dot_gradient_1D_s.F90
+++ b/src/formal/vector_dot_gradient_1D_s.F90
@@ -9,9 +9,15 @@
 
 contains
 
+  ! PURPOSE: Definition of procedure to perform mimetic volume integration of a vector/scalar-gradient dot product.
+  ! KEYWORDS: triple integral, volume integral
+  ! CONTEXT: Invoke this function in expressions of the form .SSS. (v .dot. .grad. f) * dV
+  !          with a vector_1D_t v, a scalar f, and a differential volume dV.
+
   module procedure volume_integrate_vector_dot_grad_scalar_1D
     call_julienne_assert(size(integrand%weights_ ) .equalsExpected. size(integrand%values_))
     integral  = sum(integrand%weights_ * integrand%values_)
   end procedure
+  ! END CODE CHUNK
 
 end submodule vector_dot_gradient_1D_s
diff --git a/src/formal/weighted_product_1D_s.F90 b/src/formal/weighted_product_1D_s.F90
index a802b59..23fcd4c 100644
--- a/src/formal/weighted_product_1D_s.F90
+++ b/src/formal/weighted_product_1D_s.F90
@@ -6,8 +6,14 @@
 
 contains
 
+  ! PURPOSE: Definition of procedure to perform mimetic surface integration of a scalar/vector product.
+  ! KEYWORDS: double integral, surface integral, flux
+  ! CONTEXT: Invoke this function in expressions of the form -.SS. (f .x. (v .dot. dA))
+  !          with a vector_1D_t v, a scalar_1D_t f, and a differential area dA.
+
   module procedure surface_integrate_vector_x_scalar_1D
    integral = sum(integrand%values_)    
   end procedure
+  ! END CODE CHUNK
 
 end submodule weighted_product_s