LFUN
  closure|mapping QueryExtra (mixed name)

DESCRIPTION
  Retrieve data from this objects P_EXTRA_DESC.

  Arguments:
    name: the key value to retrieve the data for.

  Result:
    The data to stored as P_EXTRA_DESC[<key>], either a mapping or a
    closure returning a mapping.

EXAMPLE
  QueryExtra("my data");

IMPLEMENTED
  /std/thing/description