This is not a question, really, but an experiment.
One problem is that it would be nice to have a tag wiki that says to not use the tag, but to have no questions marked "algebra." But if there are no questions in a tag, then the tag wiki gets deleted.
Thus far, a few dedicated people have been sure to remove every algebra-tag and replace it with its algebra-precalculus or abstract-algebra counterparts. But people keep on making them. So I thought that giving Henning's idea ( http://meta.math.stackexchange.com/questions/4472/disambiguation-pseudo-tags ), which is essentially what Martin says here, of a disambiguation pseudo-tag for algebra.
So I have frozen an algebra tag in place on a question, and am editing the tag wiki for algebra. And we'll see what happens.