| 700 / | HD | DATA PROCESSING: GENERIC CONTROL SYSTEMS OR SPECIFIC APPLICATIONS |
| 1 | DD | GENERIC CONTROL SYSTEM, APPARATUS OR PROCESS {15} |
| 56 | DD | .~ Digital positioning (other than machine tool) {5} |
| 57 | | .~.~ Alignment or registration {2} |
| 58 | DD | .~.~.~> Having position marking |
| 59 | DD | .~.~.~> Having optical sensing (e.g., image projection) |