Texting: LIS. (ph) a rude, passive-aggressive phrase, usually found at the beginning of a response, that lets someone know that they didn't listen to you. Done in convo with subordinates or anyone you disdain, because being polite to these people 'doesn't matter'. Often found in abbreviated form in response emails and texts, as LIS, indicating you think the person hasn't read or understood your post.
"Like I said, you need to get to the meeting 15 minutes ahead of time."