Oreo stands up and sprays outside against a tree trunk or bush. We first saw her do this upNorth.
When she was young, and we took her up there for the summer, she tended to get lost and not be able to find her way back home.
This then resulted in our having to go out and find her, and walk her back. She learned to spray the trees eventually, and then she never got lost again.

She does it at home too. I asked the Vet and he said some females do this. It might be from an abundance of androgens from the adrenal glands, since the ovaries are gone. She has always been a muscular active cat too. Weezie on the other hand has become porky since her spay and does not go far from home. She does however continually sniff the ground like a dog when she is outside. And Houdini is not mature yet, and will be neutered soon. He is an unknown so far in this regard.