When is a Preferential Transfer \u27Required\u27 to Be Recorded?

The BANKRUPTCY ACT of 1898 (as amended in 1903 and 1910), after defining a preference, provides in § 60b that preferences made under certain circumstances may be recovered from the preferred creditor if the latter had reasonable cause to believe that a preference was to be effected at the time of the transfer * * * or of the recording or registering of the transfer if by law recording or registering thereof is required, such time being within four months before bankruptcy. Bankrupcty courts have for years been vexed with the question: When is a transfer required to be recorded under this provision of the Act