| 968 / | HD | HOROLOGY |
| 564 | DD | INDICATING THE TIME OPTICALLY BY ELECTRIC MEANS (subclass 577 takes precedence; by mechanical means subclasses 139 and 162) [G04C 17/00] precedence; by mechanical means subclasses 139 and 162) [G04C 17/00] {6} |
| 573 | | .~ By drums or drumlike devices [G04C 17/00T] {1} |
| 574 | DD | .~.~> With date indication [G04C 17/00T2] |