LFUN
  string * AddId (string id)
  string * AddId (string * id)

DESCRIPTION
  Add one or more id strings to this object's P_IDS.

  Argument:
    id: a single string, or an array of strings to add.

  Result: P_IDS' new content.

EXAMPLE
  AddId ("sword");
  AddId (({"longsword", "elvensword"}));

IMPLEMENTED
  /std/thing/description