What do class schedule co and cl mean?

The meaning is as follows:

Cl generally means clean. co means in the schedule: night shift means night shift and compensatory time off. co means check-out in daily hotel work. It is the abbreviation of checkout. Each hotel will have its own shift schedule. In order to facilitate shift scheduling and improve efficiency, the shifts will be simplified into letters to represent them. Usually, the shifts of different departments, teams, and positions will be different. The ABCO here is not necessarily the same, but basically they still represent morning shift, normal shift, middle shift, evening shift, night shift, compensatory time off, etc. Rest and other shift conditions. According to my work experience, it may be roughly as follows: A-morning shift, B-middle shift, C-night shift, O-compensatory time off.