1. A professional thief does not "squeal": If captures by authorities in the course or as a consequence of a job, he must not reveal the identities of his partners, fences, informants, or other professional contacts. 2. A professional thief will honestly report how much money or valuables are taken in a job; he will not "burn" his partners. 3. A mob of professional thieves will share their score equally among themselves, or according to the contribution of each to the job, arranged and agreed upon beforehand. 4. A professional thief will share some of his earnings with other professional thieves who have been incarcerated (to help pay fines, bribe officials, etc.). 5. If a professional thief has valuable information (e.g., attractive targets, location of traps, and the activities of the town watch), he will share it with other professionals. 6. Professional thieves will help one another, even in spite of personal differences or enmity between them.
