what is XP?

[alfresco1]

There are numbers with a "XP" designation.
What does this mean?

When I do a search for "XP", it responds that it was ignored, because the term was too common.

[ahyangyi]

Good question.

XP, as in Windows XP, means "experience". In other contexts, it means "experience point".

On BGA, it's just another utterly less number displayed alongside your name. Supposedly, if you are having a lot fun on this site, and if you have experienced lots of kinds of fun, then you'll likely have a high XP.

Some people, however, tend to skip the "fun" part and only care about XP.