Refusal of Co-Signer (Question)

[Susan H.]

I have a rental property in a single-family residential neighborhood that's close to a fast-growing university. About 10% of the houses are rentals, and an estimated half of those are currently rented to students. We have a city ordinance restricting occupancy to three unrelated people, but neighbors report there are already several houses that violate this ordinance. The students occupying those houses are out-of-state students and (judging by their high-end SUVs and neighborhood info) come from wealthy families with parents as co-signers. This has been a hot topic at neighborhood meetings (which I attend).

I'd actually prefer not to rent to multiple students but of course cannot legally advertise "family preferred." From what I've researched, however, I understand that I can legally refuse to consider co-signers (unless a disabled person has a co-signer). My question: do I have to disclose that in my ad? Rental app?