VMS Help POSIX Threads, PTHREAD routines, pthread_attr_setname_np, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 attr

    Address of the thread attributes object whose object name
    attribute is to be changed.

 name

    Object name value to copy into the thread attributes object's
    object name attribute.

 mbz

    Reserved for future use. The value must be zero (0).