indicator; specifier; designator
Technical term used in computing, linguistics, and formal systems for a symbol or element that indicates or specifies something. Not an everyday word.
In this programming language, you specify the variable type using a type specifier.
In syntax, a designator is sometimes used to mark the head of a phrase.
length indicator; LI
clip indicator
file position indicator
Compound of 指示 (しじ, 'indication') and 子 (し, 'child; element'), likely a calque from English 'indicator' or 'specifier' in technical contexts.