A question hazardstatement element @type

[ããããããã æèç <aruga@antenna.co.jp>]

Hi,

Please tell me about the specification of @type ("trouble") of the hazardstatement element of DITA 1.3.

• The specification of the @type value of the hazardstatement element is
  "Available values are note, tip, fastpath, restriction, important, remember, attention, caution, notice, danger, warning, other, and - dita - use - conref - target ." .
• The hazardstatement element is a specialization of the note element. "Inheritance + topic/note hazard-d/hazardstatement"
• We can specify "trouble" for the @type value of the note element.

Are there any special reasons for not including "trouble" in the value of @type in the hazardstatement element?

Best regards,
Aruga