Then I tested it the other way round, but there is no way to delete that test. And now the error message on law -> legal is that there is a proposal for the other direction.
Well, https://security.stackexchange.com/tags/legal/synonyms currently says:
Users with more than 2500 reputation and a total answer score of 5 or more on the tag, can suggest tag synonyms. Users with a total answer score (total upvotes minus total downvotes) of 5 or more, can vote for tag synonyms. Suggestions will be automatically approved when they reach a score of 4, and automatically deleted when they reach a score of -2.
So it sounds like these days it is intended to be a group process.
As for the bigger issue, my first question is which do we want - law or legal. It seems like we'd want a discussion before a huge amount of retagging....
- What were the stats on them before you started retagging?
- What do other SE's use?
- Are there any tools to help us decide?
But assuming for the moment that we do agree that law should be a synonym for legal (and I actually do agree), then I can confirm that I get the same error you do when proposing that, and that seems like a misfeature for sure.
Update: According to the popups I get while choosing a tag at http://stackexchange.com/filters/17212/my-filter, legal has 1258 hits on SE, while law has 176. And @rebecca-chernoff says that the way to deal with the current situation is to down-vote the current proposal to make legal a synonym for law (at https://security.stackexchange.com/tags/law/synonyms, oddly enough, not at the legal tag) to -2 so it goes away and we can (try again to) propose "law" as a synonym for "legal". Unfortunately even though we are out of beta, few people have enough rep to do so - look at https://security.stackexchange.com/tags/legal/topusers (or is it topusers for law??) to see if you qualify. And I don't know how to interpret that page either, there are two columns of numbers - what do they mean?.... And since law has already mostly been retagged as legal, it may be impossible to find anyone who has the rep to vote. So again I conclude that this is broken, and we rely again on mods to do all this. Or at least it is insecure, since lots of people can edit tags, and edit themselves into a position to vote on something that they've demonstrated no knowledge of.....
OK, I made this synonym active. I think legal is better though I also don't feel it makes much difference either way.
In the early days of a site, it's best to rely on the moderators to visit https://security.stackexchange.com/tags/synonyms and keep things in shape there.
Suggesting a synonym is always welcome, of course, but I wouldn't stress out about not being able to push through every synonym without the assistance of the moderators so early on.