What is abbreviated bt?

Some articles on bt, abbreviated, abbreviated bt:

... BT (or similar) may stand for Baal teshuva, a term that often refers to a Jew who turns to embrace Orthodox Judaism Babylonian Talmud, a central text in Judaism (sometimes abbreviated as TB, Talmud Bavli ... a title in the British honours system abbreviated Bt Bathythermograph, a device used to obtain a record of temperature against depth in the ocean Betéti társaság a limited partnership, a type of business ... part of Scientology doctrine Brevet (military), a military term sometimes abbreviated Bt (although more often Bvt) BT tank, any of a series of Soviet military tanks ...