I had a neutered male cat that I took in as a stray when he was a year or two old. He was already neutered; we always thought his former owners waited too long and that he'd learned the spraying behavior before getting snipped.

He probably was a stray because of his spraying behavior!! Thinking back, I'm amazed that my husband didn't kill that poor cat when I wasn't looking. Twink specifically sprayed on my husband's things - his briefcase, his guitar, his stereo speakers - you name it. I did a lot of cleanup!! Twink has been gone for years now, but I STILL occasionally come across something that he marked.

I understand that spraying is a territorial, behavioral kind of thing. If there were other cats outdoors, Twink would spray like crazy to let them know this place was HIS! (and husband became husband after Twink had moved in with me, so Twink was letting him know that I was already claimed, I think!)