command letter造句

On 11 August, he issued a command letter urging improvement of the current system.
Any statement that has a Y following the command letter is processed only if the match flag is set.
Later versions optionally inserted digits between the vertical bar and command letter, indicating what version of RIPscrip was needed to interpret that command, allowing older terminals to quickly filter out non-supported features.
It's difficult to find command letter in a sentence. 用command letter造句挺难的