Help the user to choose a vector penalty bc (#26105)

framework/doc/content/source/bcs/VectorCurlPenaltyDirichletBC.md

@@ -23,6 +23,11 @@ refined and could potentially smooth out the problem data on a coarser mesh. It,
 however, has problems on refined meshes and leads to an ill-conditioned problem,
 which can be difficult to solve.
 
+Users should instead use [VectorPenaltyDirichletBC.md] or
+[VectorDivPenaltyDirichletBC.md] if they wish to set a Dirichlet boundary
+condition via the penalty method on the vector variable itself or its
+divergence, respectively.
+
 ## Example Input File Syntax
 
 !listing test/tests/kernels/vector_fe/vector_kernel.i block=BCs

framework/doc/content/source/bcs/VectorDivPenaltyDirichletBC.md

@@ -15,6 +15,11 @@ where $p$ is a scalar defining the penalty value, $\vec{\psi_i}$ the test
 functions, and $\vec{u} - \vec{u}_0$ is the vector difference between the
 current solution and the Dirichlet data.
 
+Users should instead use [VectorPenaltyDirichletBC.md] or
+[VectorCurlPenaltyDirichletBC.md] if they wish to set a Dirichlet boundary
+condition via the penalty method on the vector variable itself or its
+curl, respectively.
+
 ## Example Input File Syntax
 
 !listing coupled_electrostatics.i block=BCs