CAT II, IIIA, IIIB and IIIC requires special aircrew and aircraft certification (many times the aircraft is capable but the crew isn't). Visibility triggers a CAT II-III checklist. CAT II and any III operation cannot be conducted until all of the checklists are complete. This involves, uninterrupted power (generators on) to the approach lights, ILS and runway lights (including centerline and touchdown), visual inspection of all lighting componenets and required notifications.
CAT IIIc is 100% auto-land AND specified airport improvements are required to be designated IIIc. One of the requirements are taxiway lead-in/center-line lead-in lights.
When an airport is in this condition SMGCS (Surface Movement Guidance System) is also in effect. That is where the airport is required to have a follow-me vehicle available upon request.