I started my comment on Marty Isaacs' answer with "@Marty Isaacs". But after saving the comment, the @... disappeared. What's the reason for this behavoir of the system ?
You can find the full details on how comment notifications work on meta.stackexchange.
For this instance, the
@ wasn't necessary since the OP is always notified when someone comments. The main reason for this is that only the first
@ ping actually works in any comment; subsequent
@ symbols are either blocked or ignored. So unnecessary pings to the OP, especially potentially blocking ones, are automatically removed.