Spanish to English Bus/Financial Finance (general) Bank account statement

This comes at the top of a Venezuelan bank account statement, just underneath the Debits and Witholdings/Tax items and before the Currency (in this case Bolivares). It is alongside an item called DIF.O.BANCO

There are then a number of items containing O/B and P/B in the list of credits and debits
e.g. DEP O/B 1 DIA and DEP CHEQ P/B

I can't for the life of me figure out what these initials stand fors and yet I sense it's probably something relatively simple.