Let me get this straight. You want me to
recognise someone I've never met before?
I have trouble
recognising the face in the mirror!
The only way I might identify someone as someone I had only ever interacted online with, for example, is by something they said that only that person would have a knowledge of. Like, a PM joke we shared, or something.
If you mean have only rarely met, or only ever met once, then I would not easily recognise them again by sight. Maybe by what they said, but not by sight. I ain't that good at remembering physical details of a person.
Basically, I'm clueless!
Cheers
Mick