Quick ignore list question

Something I'm wondering about since I haven't used the ignore list yet...if I put someone on ignore, do they know I did? For example, if they whisper me, do they get a message saying that I have them on ignore, does the whisper go through for them but I never receive it, or something else of the sort? Also, would I see them talking on local/trade/whatever?

Yes, it will say they are ignored when they send you a tell.

It will take them off local and trade, but it doesn't take them off alliance or guild, and I believe group as well.

Got it, thanks.