half-dragon special breath

[astrerouge]

In the process of creating a half-emerald dragon, I saw in the draconomicon that the table had an asterisk referencing its entry in the monster manual 2 in the breath line.
Does this mean that a half-dragon breath take the special effect of the breath, in this case the stunning? Because I was under the impression that it only took the damage type from the dragon (and the form) but that asterisk makes me question that.

[Thurbane]

Races of the Dragon has a list of half-dragons (p.70), which lists a half-emerald dragon having a cone of sonic energy for a breath weapon. Generally speaking, half-dragon breath weapons only do energy damage, and do not get any special effects that the full dragon's breath weapon might have.