What's a Library Slayer?

When I was sent to the library branch where I currently work, my initial reaction was "They are sending me to the hellmouth of the library system!" After explaining to my ever supportive spouse and family that a hellmouth is where the demons and vampires of the underworld ascend to upper earth to terrorize the decent, law abiding citizens of St Paul --I mean Sunnydale--they innocently asked "Does that mean you're a Library Slayer?" While I don't like the idea of slaying libraries (or librarians) I do like the idea of being a kick-a** babe who can put unruly, foul-mouthed patrons--I mean, demons--in their place. Thus, the name, The Library Slayer.