ECPG - Clarfication of '-t', 'autocommit', BEGIN?

The ecpg man page says that '-t' will turn autocommit 'on', that
the default is that otherwise a 'commit' statement is needed to
cause a 'commit'.

In a posting from December of 2001, there was a complaint
that issuing EXEC SQL BEGIN; immediately following
CONNECT returned "BEGIN: already a transaction in progress",
to which Michael Meskes replied that it is necessary to run ecpg
*with* the '-t' switch (or, as someone else said, issue 'exec sql set
autocommit to on') if you want to BEGIN your own transactions.

Am I wrong in thinking that BEGIN-(set of commands)
-COMMIT should be equivalent to 'start transaction
-perform sequence of commands-commit result of
sequence of commands'? Or does BEGIN become
superfluous when running *without* -t? Could someone
please clarify?

Thanks.