The currently most used tag without a tag usage guidance is president (100 questions).
Many countries in the world have a president. But after looking at a few of the questions tagged with it, I noticed that most of them apply specifically to the President of the United States (There might be a bit bias at the moment due to the upcoming US presidential election).
On the other hand we also have the congress tag where the usage guideline says that it is specifically about the "the U.S. legislative body". There are other congresses in the world which have a similar function, but apparently the community doesn't consider them nearly as interesting as the US congress.
So what do we do with the tag usage guidance. Do we use the tag specifically for the POTUS or for presidents in general all around the world? If the latter, should we create a new tag us-president and start retagging most of the 100 questions currently tagged with president?