Do not hiss at me to get my attention. I do not speak Parseltongue.
Also, do not snap your fingers at me to get my attention. I am not a dog.
You may call me "miss," "ma'am," "librarian," "O Great Goddess of Information," or any other non-profanity. Just... please, if I'm going to make the effort to help you, I'd like you to make the effort to address me in a human language.