An anchoring system to lock posts into housings mounted in the ground, or to lock pipes into housings within holes through walls or foundations uses plastic collets to match post outer profiles to inner housing profiles. The collets have two gently tapered circumferential areas which lock into corresponding tapered areas in the housing. Keys help to lock the post into the collet and in turn into the housing. Customized collets match incompatible posts and housings. The anchored post may be released for re-use, with a security release system that requires the use of special tools.