If you have played Warcraft 2, there would be times when you would stmble across some random units - generally a color like yellow or teal - that when you approach them they would join you.
Basically, they are neutral players/units that don't fight or act on their own, and the player who "rescues" them first they will join.
A player can be flaged as Rescueable in the Player Properties. As mylemonblue mentioned, those units will change owner to the first player that gets close to them. You might have seen that there is triggers as well, making units "rescuable"
The term "rescue" probably comes from what kind of campaign scenarios you'll find these units, in Warcraft, maybe even more in Starcraft, and in other games as well. Very often there is a base under siege or some units in a prison or a trapped situation, that rewards you by joining you if you can reach them!
I don't think I'm dealing with quite the same pressures though, at the very least its a significantly smaller system. For the time being I'm just going to put together a quick scrubby box though and hope it works good enough to not make my house toxic
I do know this - xenforo dropped the ball by not keeping the vbulletin reputation comments as a feature. The loss of the Reputation comments data when we switched to Xenforo really was the death knell for the site when it came to all the users that left. I know I missed it so much and I got way less interested in the site when that feature was gone and I run the site.