保护码 meaning in Chinese

guard code
protected code
protection code

Protected 5 - unit numerical code for telegram service
电报用五单位数字保护码
The relationship between separation and the set of minimum distance message pairs is discovered , which leads to a theorem of sufficient and necessary condition of unequal protection . based on the definition of separation of code symbols , the large weight error patterns correction criteria of a given code is derived
其次证明了非均匀保护码的分离度和最小距离消息对集合之间的关系，进而证明了非均匀保护码存在的充分必要条件，该条件可以作为判别一个码是否均匀保护的判据。