noun
control field extension
Technical computing term referring to an extension of a control field in a data structure or protocol.
このプロトコルでは、制御部拡張によって追加のフラグを送信できる。
In this protocol, additional flags can be sent via the control field extension.
Compound of 制御 (control) + 部 (part/section) + 拡張 (extension). The exact historical derivation is uncertain; the term is used in modern computing contexts.