What is “Roy Use Only” in the book titles?

[Sergey]

Some books have strange suffix “Roy Use Only”:
Design for Human Scale Roy Use Only
Automitive Air Conditioning Roy Use Only
Practitioners Gde Pub Roy Use Only

Search shows that lots of the book titles are spoiled with it, and it’s duplicated all over the Internet.

Does it have some special meaning which is not clear to me as a non-native speaker, or it’s simply just some guy named Roy who intentionally marks his books this way, and I should remove this suffix from the book titles?

[Michael]

All of the titles appear to have been published by Van Nostrand Reinhold Company. The one book I found on Amazon with "Roy" in the listed title that has a cover image is Man & Work in Society Roy Use Only, but it doesn't have "Roy" on the book jacket.

WorldCat listings for these books don't have "Roy" in the title.

I have no idea what the "Roy" suffix means, but I'm guessing it's jargon for that publishing house. I think you're safe to delete it from those titles you find it in.

[Sergey]

Thank you!