It depends what you put on the tracks. The track itself isn't a problem. Regular track light heads are not pendants. You can get pendant adapters for track lights, but they're pretty uncommon in residential use. As you understand pendants are not allowed in clothes closets (a pendant connects the luminaire to the structure with a cord).

Most track light heads have open or partially enclosed bulbs. If these bear incandescent bulbs (including halogen), they may not be used in clothes closets. If the BULB is fully enclosed or it is not-incandescent (LED or perhaps CF), then it is allowed.