The graph tag is supposed to be for questions about the graphs of functions. But it is very commonly misapplied to questions that are about the graphs of graph theory. These questions are supposed to have the graph-theory tag instead. Many don't.
Many questions have both tags. There are between 50 and 100 questions tagged with both graph and graph-theory, and I would be surprised if both tags were appropriate for even one of these.
The graph tag is usually wrong. I suggested in the "tagging" chat that we:
- Eliminate graph
- Replace it with something less ambiguous: perhaps function-graph, or perhaps just eliminate it
- (My current favorite suggestion is that we replace it with graphing.)
- Blacklist it to prevent further confusion
I suggested this in the "tagging" chat. Martin Sleziak, the person who seems to have given the most thought to tagging issues, replied:
It is good that you have mentioned this problem. I've retagged a few questions (but there is a lot of them remaining.) I've also added a comment template here. If you think that the graph tag should be blacklisted, you should probably start a meta thread. Blacklisting a tag is a big decision, so the community should know about it and it would be good if some consensus could be achieved.
I thought about it some more, and here we are. There are a few hundred questions tagged with graph, so it would not be an insurmountable task to eliminate them manually. Around one-sixth of these also have graph-theory, and we might decide, as a first step, to mechanically remove graph from each of those; this would be correct in the great majority of cases.