cost mark
noun1
Any of a series of usually arbitrary codes used by jewelers to communicate prices secretly.
- The first was found to contain $10,000 of diamond mounted goods, each piece still being tagged with Shoop's private cost marks. The second package contained nine papers of loose diamonds, valued at $6,000, […]1913, Credit & Financial Management, volume 13, page 789:
- 82 assorted finger rings with various cost marks some of which are as follows: […]1922, The Jewelers' Circular, volume 85, number 1, page 89: