LFUN
  mixed QueryExtraEntry (mixed name, mixed prop)

DESCRIPTION
  Retrieve data from this objects P_EXTRA_DESC.

  Arguments:
    name: the key value to retrieve the data for.
    prop: the field name to retrieve the data from.

  Result:
    The data to stored as P_EXTRA_DESC[<key>][<prop>].

EXAMPLE
  QueryExtra("my data", P_SHORT);

IMPLEMENTED
  /std/thing/description