3.3.1. Next, the requestor's permission to update the RRs named in the Update Section may be tested in an implementation dependent fashion or using mechanisms specified in a subsequent Secure DNS Update protocol. If the requestor does not have permission to perform these updates, the server may write a warning message in its operations log, and may either signal REFUSED to the requestor, or ignore the permission problem and proceed with the update.
3.3.2. While the exact processing is implementation defined, if these verification activities are to be performed, this is the point in the server's processing where such performance should take place, since if a REFUSED condition is encountered after an update has been partially applied, it will be necessary to undo the partial update and restore the zone to its original state before answering the requestor.
3.3.3. Pseudocode for Permission Checking
if (security policy exists) if (this update is not permitted) if (local option) log a message about permission problem if (local option) return (REFUSED)