SS c9.2 says 'Qualifying spaces must meet the requirements for outdoor air quality enumerated in IEQ c5.’ Does this mean a project has to meet IEQ c5 in order to achieve SS c9.2?
No, the credit is specific about the outdoor air quality requirements. IEQc5 goes into more detail and may not be applicable. For example, entries into and out of the building need to be protected according to IEQc5 if you are documenting that credit. If your project is not and you are documenting sSc9.2 then you don't need to describe entry mats.