 Months could go by until the captain's recommendation made it back to the Department of the Navy, was acted upon, made official, and news sent back.In the intervening time, the officer recommended for promotion would be accorded the privileges and authorities of his "new" rank, but would not receive the pay for it, since it was not yet official.Because it was not yet official, and because he was still wearing the old frock coat of the recently departed and (officially) promoted officer, the officer recommended for promotion was considered "frocked".