An ST format optical connector for terminating an optical fiber comprises a housing configured to mate with an ST receptacle or coupling, the housing having an ST bayonet-style format. The ST format optical connector also includes a collar body and a retainer disposed in the housing, where the collar body is retained between the housing and the retainer. The housing is prevented from fully rotating about the collar body and retainer. In addition, the connector can be deactivated for fiber repositioning or reuse.