Is it normal to cover bathroom tile with a paint like substance?

i jusnoticed that my landlord has certain spots in the bathroom covered with a white paint like substance. Under the shower handle, she has a thick white guey like substance as if she was trying to cover something dark. The bottom of my bathroom tub is also rusted. Is this acceptable? And for what other reason could she be covering tile with paint other than to cover up mold? How do I know for sure? Thanks.|||Sounds like an El Cheapo landlord. Use a little rubbing alcohol on a cotton swab on the title to detect mold. Also, you can call your local department of health and safety to discuss if the rusted tub is a safety code or federal violation against the landlord, and what potential actions that you can take.