Library /sys$common/syshlp/pca$help.hlb MERGE, Parameters  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 input-file-spec

    Any valid OpenVMS file specification that identifies the files
    you want to merge or to take ANC information from. Wildcards may
    be used in the file name and/or in the extension. If you specify
    the /SPM_PROCESS_ID qualifier, then the local node, current
    default device and current default directory are assumed as the
    default for each of the input file-specs provided, and default
    file name extensions are not applied. If you do not specify the
    /SPM_PROCESS_ID qualifier, then the same defaults are assumed,
    but the file name extensions default to PCA.