Currently, the tags counting, enumeration and enumerative-combinatorics are synonyms of combinatorics. This reflects what combinatorics was considered to be maybe 100 years ago, but modern combinatorics is about much more than only (or mainly) counting.
As an example, this is a selection of topics from the table of contents of two reputable books on combinatorics:
- J. H. van Lint, R.M. Wilson. "A Course in Combinatorics": Graphs, Colorings of graphs and Ramsey's theorem, Flows in networks, Latin squares, Hadamard matrices, Codes and designs, Strongly regular graphs, Projective and combinatorial geometries, Association schemes.
- Peter J. Cameron. "Combinatorics": Latin squares, Finite geometry, Ramsey's Theorem, Graphs, Designs, Error-correcting codes, Graph colorings.
What do you think?
Also: How is the removal of a tag synonym done technically? I did not find any detailed information on this.
I found this old discussion from 2010 which I guess led to the creation of the synonyms. The main point in the discussion appears to be that there have not been enough questions to justify a distinction of counting and non-counting combinatorial questions. This has been a long time ago and certainly is not true any more. Today, there are more than 50,000 questions with the combinatorics tag.
The has been a discussion on whether it makes sense to have discrete-mathematics to be a synonym of of combinatorics. This is a pretty similar case, and the 40+ answer shows a clear consensus against that synonym.
I just spotted the independent tag for infinitary-combinatorics, without any synonyms. Given that, I think that enumerative-combinatorics as arguably the most important branch of combinatorics, also deserves to have its own independent tag.