I was asked to review an edit on a tag which has only a single question. Turns out it is a duplicate tag because both regex and regexp exist. Should I approve an edit to create a description on a duplicate tag, or should I reject the edit explaining that a merge is more appropriate?

Secondly, how could I get those two tags merged? Apparently I don't have sufficient reputation to even suggest that the tags get merged (either that or I don't know how to do it). I tried suggesting regexp as a synonym for regex, but I am not allowed to suggest that.