In most cases, students who are requesting accommodations are receiving services from Disabilities Services. This office requires documentation of the specific disability from the student's medical doctor, psychologist or certified evaluator. Unless the student discloses his or her specific disability to you, as an instructor you are not entitled to the specifics of this information. If a student is requesting an adjustment from you, an electronic accommodation should have been received at the beginning of the semester stating that s/he indeed qualifies for academic adjustments.
Students requesting accommodations on the basis of a disability must be registered with Disabilities Services. It is recommended that you not agree to accommodations until you have electronic documentation from Disabilities Services. Other disability-related documentation may be valid, but the process of accommodation must be uniform throughout FSU.