For Swedish Open categories couples and solo you choose your class according to your birthday. (For example if you are 15 years old on 2nd of March, you choose U16.)
For Basic Categories you choose your class according to the year you are born in.
Juvenile/Barn - 2012 or later
Junior - born 2009-2011
Youth - born 2006-2008
Amateur - born 2005 or before
Seniors 1 - one born 1989 or before, another 1994 or before
Grand senior - one born 1969, another 1974 or before
U12 and juvenile - only basic steps (WDO, WDC, WDSF)
E-basic Waltz/Cha- Cha
D-basic Waltz, Quickstep/ Cha-Cha, Jive
C-basic Waltz, Tango, Quickstep/Cha-Cha, Rumba, Jive
B-basic Slowfox and Viennese waltz, open Waltz, Tango, Quickstep/basic Samba, Paso, open choreography Cha-Cha, Rumba, Jive
Your are allowed to dance only restricted choreography (basic steps) in level E, D and C. In Level B you are allowed to dance open choreography in Waltz, Tango and Quickstep/Cha-Cha, Rumba, Jive.