We currently have two tags which apparently address the same object ---
diagrams. While there's a semantic difference between the two (in content/representation), it's all the same for LaTeX.
I suggest we use
figures for questions related to external stand-alone files (e.g. PNG, PDF, EPS) that you cannot edit within LaTeX, and to use
diagrams for those that are produced by e.g.
psticks, or whatever.
Alternatively, we can just use
diagrams tag as a synonym for