I thought that tag synonyms were meant simply to be proposed and left to survive or die on their own, but I see [another question](https://meta.mathoverflow.net/questions/4912/should-tagfeynman-integral-be-a-synonym-of-tagpath-integral) in HNQ about tag synonyms, so maybe one is supposed to raise a corresponding Meta question.  I think that [tag:positive-characteristic] and [tag:characteristic-p] are synonyms.

EDIT:  As @MartinSleziak [points out](https://meta.mathoverflow.net/questions/4927/positive-characteristic-and-characteristic-p-are-synonyms#comment25243_4927), I perhaps stated this a bit vaguely.  Concretely, I already [proposed](https://mathoverflow.net/tags/characteristic-p/synonyms) the synonym, and it awaits the necessary votes.