Hi,
as far as I remember ET:QW will hold the XP permanent.
BF2 also holds the XP of a player permanent.
On a wesite for BF2 I found the following:
If groups of players work together it’s possible to get very fast high XP points.
They kill, revive, kill, revive, throw ammo packs, kill, revive, kill, revive and so on.
I think it’s a terrible exploit.
Not sure how to prevent this.