Weird text in chat in-game?

I was playing a game earlier tonight, and at some points in the game there was some sort of yellow text in chat (as if I was being messaged by a friend or something). I don't remember what it said exactly, but I asked the rest of my team if they've seen it, and at least one person said yes so I don't think it's just me. If anyone else has seen it, please put it in the comments and hopefully Riot will notice.