The first startup I worked at used IRC - well before slack etc. I hadn’t touched it since I was a teenager and think I managed to violate just about every internal channel guideline. Took me a minute to understand what “echan” meant.
edit: some wider-range searching suggests it might be Spanish for “kicked”.
It's considered bad etiquette because IRC channels are often quiet but still active - you're supposed to stick around and just ask your question directly rather than bailing when you don't see instant chatter.