HUD Handbook 4350.3 § 4-29

When an applicant requests an accessible unit or a unit preference, such as a first floor
         unit, the owner may conduct inquiries to:

        A.       Verify that the applicant is qualified for the unit, which is only available to persons
                 with a disability or to persons with a particular type of disability. For example, an
                 applicant with a physical disability who uses a wheelchair may not be eligible for
                 a unit that is specifically designed and intended for a person with a visual
                 disability.

        B.       Verify that the applicant needs the features of the unit as an accommodation to
                 his or her disability. For example, an individual with a psychiatric disability
                 (assuming no physical disability) requests a unit with features designed to be
                 accessible for individuals with mobility disabilities. In this situation, there is no
                 relation between the individual’s psychiatric disability and the need for an
                 accessible unit. Although an alternate accommodation may be required to
                 accommodate the applicant’s psychiatric disability, the applicant would not be
                 entitled to the accessible unit requested.

NOTE: Owners may not request information about an applicant’s type of
                 disability but may identify an applicant’s need for the features of accessible units
                 or for a reasonable accommodation.

        C.       Verify that the applicant is qualified to receive a priority on the waiting list
                 available to persons with a disability or to persons with a particular type of
                 disability. If the owner gives a priority to a class of persons, and an applicant
                 indicates that he or she is qualified for the priority placement on the waiting list,
                 the owner may screen to verify that the applicant qualifies for the priority
                 placement.