delineator
n. 描写的人;描绘器;裁剪用图样
例句
The x is the delineator between standard enumerations and extensions.
X 是标准枚举和扩展名之间的界限。
The x: is the delineator between standard enumerations and extensions.
是标准枚举列表和扩展列表之间的描绘程序。