Just wondering if it is acceptable for me to ask a fairy not to post my garden address on her back wall

Many post other garden links on their back wall as they plan to visit it often, it's an alternative to adding to favourites.

That is a tricky one. I post garden links on others back walls if I discover a garden that might be helpful to them and I do the same on my back wall if I discover an unadvertised garden that might have what I am looking for and want to check later. If you are a public garden, you really can't ask anyone not to visit as this game works on the spirit of co-operation. I do not favourite gardens as I would have to remove one of my regulars...so this gets around that. I guess that you would have to examine why you don't want your garden link posted on someone's back wall. If it is there for someone and their friends to harass you, then I would suspect that you could report the link being shared and moderators would decide if appropriate and could remove the post if warranted. If you don't want the garden link there because it means that you will have more visitors and you wish certain people only to water, then becoming private or friends only would be the option to take.

If you want a definite answer as to whether this action is sanctioned, just drop Fairyland Support a note and ask for their advice.

You can report the note and ask FL to remove it and they will

Have you asked them?

No, can't fathom the rationale.

I have done it occasionally when wanting a quick reference to a garden or sent it to someone for them to go there if the said garden hasn't advertised. Also, when i did Alice, i had a whole heap of them on my back wall as couldn't fit them in my "favourites". I would just ask them why they have it and i'm sure there's a good explanation. :)

If it makes you uncomfortable just ask politely for it to not be done. But I do not believe its a violation of any rules so in the end it would be up to the person as to why they did it. I don't do it myself but have several friends who do so they can easily visit to hunt.  If they are harassing you that is different. And you report it.

I do it from time to time so I can visit the garden when I switch devices (computer vs. phone) - I don't want to add to my favorites because that takes time to find and memory to know which one I want.