(This is a reply to Stefan's answer, but too long for a comment.)
Stefan is correct that the headings tag could feature hundreds of questions in a few years -- right now, the tag with the highest number of questions, tikz-pgf, is already at 318 questions. Stefan is also (obviously) correct about the availability of tag navigation and the fact that a question can feature up to five tags. But my proposal was motivated by the very aim that is also important to Stefan: ease of access to particular questions. So let's take a second look at the current tagging situation for headings & friends.
\chapter, Stefan has a point in that this macro is implemented in a different way, and that this fact is mirrored in numerous question tagged with chapter. Here's an example: Chapter starts on right hand side. On the other hand, there are questions that offer advice which is also valid for lower-level sectioning commands. Again, an example: How can I display a short chapter name in the header and a long chapter name in the TOC?. Note that this question does not featute the headings tag, presumably because the questioner was not aware of its more general nature. My point: Even if an additional chapter tag may well have merits, the "broad" concept tag should not be omitted. (Note: Everything I said about
\chapter is also valid for the
\part macro, which has not necessitated a parts tag up to now.)
Assuming that the chapter tag should be preserved does not equal preserving the current situation as a whole. I still maintain that the breakdown of questions into headings vs. sections happened by rolling the dice, and that a special sections tag is a stumbling block for accessing relevant answers about headings in general.
My revised proposal thus is: Merge sections and headings into a new concept tag called sectioning. Keep the chapters tag, but add the sectioning tag to every question tagged with chapters because numerous of these questions are also relevant for lower-level sectioning commands (and because "normal" users cannot assess if this is the case for their particular question about
\chapter). And yes, add a parts tag. :-)
EDIT: Used sectioning as new term for the broad concept tag.
EDIT 2: Changed part to the plural form parts.
EDIT 3: I ask a moderator to do the following:
Make sections and headings synonyms of the new concept tag sectioning. (I have already created this tag.)
If it can be done automatically, add the sectioning tag to every qestion tagged with chapters but do not remove the chapters tag. (I suspect this will have to be done manually in the course of the next weeks.)
EDIT 4: The latest proposal, which will be implemented by manual retagging in the next few weeks, is a general sectioning tag plus the specific tags parts, chapters, and sections-paragraphs.
EDIT 5: Also, some of the questions currently tagged with paragraphs (which deals with
\par) will have to be retagged as sectioning sections-paragraphs.
EDIT 6: Moderators: The question can be tagged as status-completed.