In character coding system, a method of increasing the number of characters which can be associated with a given number of bits. If a 6 bit code is used then 64 characters may be allocated, however, if two of these characters are designated as “shift” and “unshift” then they may produce the effect of a shift to and from an alternative character set giving a total of 124 available characters.; 在字符編碼系統(tǒng)中,給定位數(shù)后增加可編碼字符個數(shù)的一種方法。如果采用6位碼,就可以分配64個字符; 但是,如果其中兩個字符分別表示“移位”和“非移位”,就可以給出124個字符代碼。參閱escape code。