Combination of a coded wingtag (colours see below) on both wings.
note 1 : used code is a two numeric one.
note 2 : used colours are :
* 2004 : orange tags, black code.
* 2005 : yellow tags, black code.
* 2006 : green tags, black code.
* 2007 : purple tags, white code.
* 2008 : red tags, white code.
* 2009 : blue tags, white code.
* 2010 : pink tags, black code.
* 2011 : black tags, white code.