The following is a list of GCE Ordinary Level subjects offered by Cambridge International Examinations (CAIE). Cambridge O Levels, Cambridge IGCSE and/or Cambridge International Level 1 or Level 2 Certificates may be taken in the same examination session but certain combinations of subjects are not allowed as described below. Cambridge O Levels are only available for centres in administrative zones 3, 4 & 5.(This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by adding missing items with reliable sources.)