Not without JS, that I know of.

@snufkin3 notes1 reply1 tag, 0 users following1 followerNo bio yet.enter to follow7d · 1 replyenter to reply

I think one thing could be done in post text-area, that hashtags and mentions should be suggested if user types '#' or '@' and then starts typing. Although I know this would be already in the list. Right @stagas72 notes299 replies28 tags, 198 users following71 followers |\__/,| (`\ _.|o o |_ ) ) -(((---(((--------enter to follow 8)