An inadvertant overdraft took place recently, when an overdraft (no prior arrangemnet existed) for $2,500 was made to a Director. This is apparently in contravention of Regulation-O section 215.4(e). Is this overdraft required to be reported to the Board? What section/subsection supports the requirement of reporting it to the board or for not reporting it?

There is no requirement to report it to the Board. But I think it would be best if management informed the baord that they had a Reg. O violation rather than your regulator.