There are two classifications of phantom cats at Wildrun.
First, there are the cats still wandering around the farm, a product of dumping. Oh, how I look forward to the day when I catch the next person dumping a cat! I think our court system is now such that the person definitely would end up with "animal cruelty" tagged on their record, which is not so cool when you have to fill in that "have you ever been convicted of a crime, if so, what?" question on job applications.
I tend to think of these cats as Wildrun cats, even though they are still at large. They need to be on my radar, to get caught, get fixed, and get homes.
The second are adult cats I have sent away with past adopters and friends, to bring them out of their shells. They are cats that were getting more shy here, not more friendly. Sparkles and Charlie are two of these. What usually happens in these cases is the foster home comes to see the cat as theirs, and well, they end up sort of pseudo-adopted. But it's really not fair on my part not to check in more often, just in case the person has had enough. I've only had one or two come back in the past, and they do come back much happier and less skittish.
So believe it or not, I did set a computer alarm to check in on my cats that are on "vacation." If they aren't still hiding under the couch, maybe I can get some pictures.