The e.t tag is malformed if one looks closely.
It appears that tags cannot be created(or renamed) to end in punctuation. This seems almost too trivial to bring up; but, as every other acronym-as-tag has no periods (e.g., dcau, tv, ai, rpg), it sticks out a bit as a sore thumb.
I'm somewhat of the mind that et looks awry, but it was suggested on chat that I post for opinions. Rename or no? And is it absolutely impossible to allow tags to end in '.'?