abbreviation
1. of course
2. office copy
3. officer candidate
4. officer commanding
5. officer in charge
6. officer's cook
7. official classification
8. old charter
9. old crop
10. on center
11. often not capitalized only child
12. open charter
13. open cover
14. often not capitalized
[Latin opere citato ]
in the work cited
15. order canceled
16. original cover
17. outing club
18. overcharge
19. oxygen consumed