In the Netherlands:

Military medals:
-Black tie....never.
-White tie...miniatures, but only when stated on the invitation.
-Daywear jacket, only on liberation day, veterans day and rememberance day...full medals.

Unit citations for bravery (Miltary Williams Order) are only attached to the unit or branch banners...these are close to holy and all (including the queen) must salute (or bow to) them.

Civilian medals (Royal household orders, Knighthood orders):
-Black tie...never.
-White tie...the whole shebang.
-Daywear jackets...small button hole ribbon or nothing.