Is it customary to "tip" the ear of a TNR'd cat?

My little Eva was brought to a rescue group by a couple whose garage she had run into. They cared for her for a few weeks before they found Adopt-a-Cat. When the Adopt-a-Cat ladies brought her to a vet to be spayed, the vet shaved her and found a spay scar.

The very tip of her left ear is squared off, like it had been cut very carefully. Before I came to this board, the bf and I assumed that she had either been bitten or abused in her past life. Now, though, I seem to recall a mention of clipping the tip of the ear of ferals that have been TNR'd. Also, from reading various descriptions of feral behavior, I'm beginning to wonder if Eva was, indeed, wandering around on her own for so long that she was becoming feral and thus was TNR'd.

It doesn't matter all that much anymore, really, as she continues to integrate well into our family. I'm just curious if this is a customary practice, and if that would explain some of her behavior. Thanks!

yes it is customary. It is an easy way to tell if the cat has been neutered or spayed. They used to tattoo them, but the tattoo's wear off in time, and the fur grows back and covers it. They only take off the bare tip of the ear and it heals in nothing flat and the cat is fine afterward. In large feral cat colonies that are managed you will see every cat there with a tipped ear.

Yes it is, it's the nationwide symbol for a fixed feral. Here's a photo of one of our ferals we tamed and put up for adoption. Look at her left ear and you'll see it is tipped.

Ok, that's helpful. I knew it was *a* symbol, I just wasn't sure how wide-spread it was. Thanks!

ETA: Ooh, she's beautiful!