registration mark

Short definition from Wiktionary

Noun

1. 1
   A symbol representing a registered trademark; ®.
2. 2
   Any marker used for alignment or registration during printing, often shaped like a crosshair; ⌖.
3. 3
   Any marker used for alignment or registration during printing, often shaped like a crosshair; ⌖: Synonym of traffic light (“the colored dots on stamp sheet margins printed with offset printing or photogravure methods”).