quoted-literal1

    A string enclosed within double quotes that is the file
    specification of a macro library. If a logical name exists and
    it is the same as the macro library name, specify the .MLB file
    extension to override the logical name.

 quoted-literal2

    An optional string enclosed within double quotes that specifies
    a search list of file specifications where the assembler should
    look for the specified macro library. The assembler successively
    processes the search list in left-to-right order and attempts to
    locate the specified macro library in each location specified in
    the search list until the macro library is found. If the macro
    library is not found, the assembler issues a diagnostic message.
    If you omit the second argument to the .LIBRARY directive, the
    assembler uses the following search list by default:

    o  The current device and directory

    o  The device and directory specified by the logical name
       MACRO64$LIBRARY (if defined)

    o  The device and directory specified by the logical name
       ALPHA$LIBRARY (if defined)

    o  The device and directory specified by the logical name
       SYS$LIBRARY

    Logical names may be defined as OpenVMS search lists.