Library /sys$common/syshlp/acledt.hlb F13_KEY  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    DELETE TO BEGINNING OF WORD (F13 or linefeed)

    Deletes all characters from the cursor position to the beginning
    of the word containing the cursor. All the characters deleted are
    stored in the delete word buffer.