shop talk

from the GNU version of the Collaborative International Dictionary of English.

• conversation about a matters pertaining to person's occupation; -- often used of such discussions when conducted outside of working hours, as in social gatherings.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun uncountable discussion about one's trade, business, or employment that only others in the same field can understand

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun talk about your business that only others in the same business can understand