/USER_GROUPS=option[,...]

    Restricts access (from the local node) to service nodes in the
    network that belong to the specified groups. Your local node can
    access only those service nodes associated with the user groups
    specified. The /USER_GROUPS qualifier also serves to limit the
    number of nodes stored in your node's node database. (The local
    node only stores information about the nodes and services that
    belong to at least one of the specified user groups.) By default,
    all LAT service nodes belong to group 0.

    This qualifier affects your local node when outgoing connections
    are enabled (/CONNECTIONS=OUTGOING_ONLY or /CONNECTIONS=BOTH).

    Use the SHOW NODE command for a list of the user groups (service
    groups) enabled for your node.

    The /USER_GROUPS qualifier has several options. For each option
    described here, you can use two ways to specify more than one
    group:

    o  List them separated by commas

    o  Specify a range

    ENABLE=group-      Gives your node access to the listed user
    code[,...]         groups.
    DISABLE=group-     Prevents your node from accessing the listed
    code[,...]         groups. The listed groups were enabled
                       previously.
    ENABLE=group-      This option lets you enable certain groups
    code[,...],        and disable other groups in one command
    DISABLE=group-     line: gives your node access to the groups
    code[,...]         listed with the ENABLE option and prevents
                       your node from accessing the groups listed
                       with the DISABLE option. Enclose both ENABLE
                       and DISABLE in parentheses; for example,
                       /GROUP=(ENABLE=(10,12),
                       DISABLE=(1-30)).