touchmark

Noun

1. The manufacturer's official identifying sign, impressed into a pewter object.
   • For quality control, Parliament in 1503 required all London-made pewter to be stamped with the maker's symbol or touchmark. - 1988 Dec. 1, Susan G. Sawyer, Photog Pewter the Time-Honored Way," New York Times (retrieved...
2. A symbol, sign, or other inscribed indication used to aid the alignment, calibration, or other adjustment of a measuring device or scientific instrument.
   • The instrument used was a refracting telescope by Dollond. . . . The cap containing the diaphragm was furnished with a touch-mark consisting of a projecting spoke. When in adjustment as described above this mark was...
   • The initial touch-mark was established at Roper's saw-mill, on the North River, and is a point on 20-penny nail driven flush with the horizontal surface of sill to bull-wheel. - 1880, "Survey of the Albemarle and...