职能号是保留上下文索引系统（PRECIS）控制其标引句法的重要工具。

The roles of PRECIS are important devices to control the syntax in subject indexing.

youdao

职能号是保留上下文索引系统（PRECIS）控制其标引句法的重要工具。

The roles of PRECIS are important devices to control the syntax in subject indexing.

youdao