I usually separate the Teradata load and unload utilities into 3 groups:
Multiload, Fastexport and Tpump: Although each of these tools have their own set of commands, they have also a common set of command that work identical for the 3 tools. This is the case of ".ACCEPT" command. The commands syntax is common to 3 as well.
Fastload: Has its own set of commands and its own syntax.
Bteq: Has its own set of commands and its own syntax.