/sys$common/syshlp/helplib.hlb READ, Qualifiers, /NOLOCK  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Specifies that the record to be read not be locked and enables a
    record to be read that has been locked by other accessors.

    By default, records are locked as they are read and unlocked on
    the next I/O operation on the file.