LFUN
  void SetExtraEntry (mixed name, mixed prop, mixed data)

DESCRIPTION
  Store data in this objects P_EXTRA_DESC.

  Arguments:
    name: the key value to store the data under.
    prop: the field name to store the data.
    data: the data to store.

  The function stores <data> as P_EXTRA_DESC[<key>][<prop>].

EXAMPLE
  SetExtraEntry("my data", P_SHORT, ({ "(worn)" }) );

IMPLEMENTED
  /std/thing/description