VMS Help SCA, DELETE, LIBRARY, Parameter  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 library-spec[,...]
    Specifies one or more libraries to be deleted. The library must be
    one of the current SCA libraries established by the SET LIBRARY
    command. You can use a library number in place of a library
    specification. For example, the primary library is library #1.
    You can also specify a wildcard name expression.