Library /sys$common/syshlp/sca$neutral_help.hlb SCA Topics, Glossary, primary_library  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    The first library in the library list. Commands which change the
    SCA library, such as LOAD and REORGANIZE, apply to the primary
    library, unless you use select a different library.