There's a proposed edit somewhere that would create an "engineering" tag. I don't see any value in such discipline-specific tags, myself. I suspect that at the level of creation of documents, then I (as a mathematician) could learn a lot from the chemists and others around here. Even if I don't want to typeset H_2 SO_4 all that often, the techniques used to do it could be useful for typesetting, say, the Riemann curvature tensor (yes, yes, I know).
So my inclination would be to reject this edit. However, I can well imagine that there are reasons for such tags that I've not thought of (having spent all of 20s thinking about it). So if anyone would like to argue in favour, or more strongly against, I think it would be useful to see those arguments. Thus:
Is there a use for such tags?
(The question in question, for those who like a concrete example, is Drawing Mechanical Systems in LaTeX)