A state-dependent encoding method used in telecom protocols, such as GSM SMS, to switch the interpretation of bit patterns to an alternate character table. Unlike a single-shift character that only affects the very next byte, a locking shift applies to all following bytes until another shift command is received. This allows limited bandwidth channels to support multiple languages or extended symbol sets efficiently.
If the locking shift byte gets corrupted in transit, the rest of the text message turns into garbage characters.
Related terms
Escape character
A specific control code that changes the meaning of the data immediately following it.
Escape sequence
A specific string of characters used to send control instructions rather than text data to a terminal or device.
GSM
Global System for Mobile communications is a standard for digital cellular networks.