The Dress code is strictly according to Rule 12 of the WDSF Competition Rules:

Rule 12
Competition Dress
For all WDSF granted competitions under RULE 5, as well as for all DSE CHEGP competitions, competitors dress applies according to the WDSF Dress Regulations. These WDSF Dress Regulations are components of the WDSF competition Rules
The chairman, or the WDSF Sports Director, has the right to disqualify any couple at the competition not dressed according to this Rule. Furthermore the Presidium is entitled to suspend such couples from competitions for a limited period of time strictly according to Rule 12 of the WDSF Competition Rules:
Rule 12
Competition Dress

For all WDSF granted competitions under RULE 5, as well as for all DSE CHEGP compeetitions, competitors dress applies according to the WDSF Dress Regulations. These WDSF Dress Regulations are components of the WDSF competition Rules

The chairman, or the WDSF Sports Director, has the right to disqualify any couple at the competition not dressed according to this Rule. Furthermore the Presidium is entitled to suspend such couples from competitions for a limited period of time.