Traditionally only members of the Royal House, from the age of 18, do attend Prinsjesdag.
At present there are only a handful members of the Royal House
being 18 years and older:
HM The King
HM Queen Máxima
HRH Prince Constantijn
HRH Princess Laurentien
HRH Princess Beatrix *
HRH Princess Margriet*
Professor Pieter van Vollenhoven LL.M.*
* Princess Beatrix has abdicated the kingship and together with her also her sister and brother-in-law have slowed down their public agendas.
The dresscode was jacquet (civil) or grand military tenue. The King and his brother were in civil wear, in jacquet (= morning dress). In combination with that grand decorations are never worn. In their lapels, the King and the Prince wore miniature versions of their orders, a so called bâton. When Queen Máxima and Princess Laurentien were in normal day-dress, they would have worn these bâtons too. But they were in long day dress and then the grand decorations can be worn.
On the picture below you see an Order (Officer in the Order of Orange-Nassau). Such an Order is effectifely only worn on a military tenue or when attending a white tie event. Besides it, you see a bâton, a miniature. That can be worn in the lapels or on a neat dress when attending more formal events:
http://www.eindhoven.nl/upload_mm/4/7/0/52867_fullimage_ko.jpg
In this picture you can see the bâtons in the lapels of both the King and the Prince:
http://www2.pictures.zimbio.com/gi/King+Willem+Alexander+King+Willem+Alexander+jZN1VHN8T6qx.jpg
In 2012 the (then) Prince of Orange appeared in military tenue, then grand decorations can be worn. It gives a more complete image indeed:
http://www.haagsefotos.nl/html/prinsjesdag/prinsjesdag2012/images/prinsjesdag-2012-113.jpg
Oh, I would say they run neck and neck. The pagentry is magical and gives the country a reminder of who their royal family is and how it affects their democracy.
