[bigwavedave]

Anytime my boss has sent me a '?' with no context, I've always responded with a '?' of my own. Context has always been forthcoming afterwards.

[lucisferre]

And they keep doing it?

?

[bigwavedave]

Yep. It's become more of a "hey you, look at me" kind of thing for us with my '?' being a "yo, you've got my attention- what's up?" kind of response. It works this way for him and I, but I wouldn't expect it to be an inherent shorthand in any of my other relationships.