Here's something fun: the recent post on iLibrarian (one of my favorite blogs) covers "6 Terms that Instantly Reveal You as a Librarian."
I'm as much a fan of stereotypes as the next guy - especially in the "your language is your identity" theme - and some of these really made me laugh for how spot-on they were:
- Primary Sources
The only people I've heard use "primary sources" are academics, or students of academics who were told to find primary sources but have no idea what they are.
I would submit a few more, too: serials, definitely (and even periodicals for that matter); databases; pathfinder; bibliography.
What kind of librarian jargon do you think makes us stand out?