VMS Help TCPIP Services, TELNET, TN3270 Keyboard Functions, ER_INP  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    VT100: EXT + KP-            VT200: EXT + F18
    DEFINE_KEY Function: ERASE_INPUT

    On a formatted screen, clears all the data in the unprotected
    fields on your screen and moves the cursor to the first position
    in the first unprotected field on the screen.

    On an unformatted screen, clears all the data and moves the
    cursor to the first position on the screen.

    You can also use the ER INP function to remove all previously
    recorded key sequences by using the RECORD function and then the
    ER INP function.