The tool blocked all commands from the write category sent to a protected drive. However, the tool did not block some commands from the miscellaneous category that are either undefined (invalid) or outmoded and not routinely used by current software. These commands in current BIOS implementations do not write to a hard drive, but in the future they could be defined such that they would change the contents or accessibility of a protected drive. In the test specification, these commands are therefore included in categories that should be blocked.