What is the difference between OBV (Old Babylonian Version) and SBV (Standard Babylonian Version), in Babylonian texts translated to English ?
Is SVB a standardized translation or standardized form of Babylonian vocabulary/grammar/literature ?
It's not about translation per se, but about which text they're using, and the dialect/era that text was written in. From Huehnergard's A Grammar of Akkadian:
Old Babylonian is the Akkadian of southern Mesopotamia during the period of the first dyntasty of Babylon.
Already during the Kassite period Old Babylonian had come to be regarded as the classical period of Akkadian language and literature, and scribes in both Babylonia and Assyria attempted to duplicate it in a purely literary (i.e., unspoken) dialect that Assyriologists call Standard Babylonian (SB).
OBV would mean texts written in the Old Babylonian dialect, while SBV would refer to later texts when Old Babylonian was no longer spoken but the language of the text still tried to imitate it. Works like the Epic of Gilgamesh sometimes go through a few revisions as its transmitted through the centuries. These descriptions are provided so that you know from which recension the translator is working.