No matter how great your ride if you have a whip or bit that does not pass inspection you are out.  Here are a few quick rules from the 2006 USEF rule book that will help you stay legal in the Dressage show ring.

Whips

• My not exceed 43.3 inches with the lash (the little bit of string on the end)
• No Whips in FEI level classes
• No Whips in championship classes and most qualifying classes, ask show management if you are unsure 
• Check out a few whips in my store: http://stores.ebay.com/Equestrian-Wholesale_Whips-Crops_W0QQcolZ4QQdirZQ2d1QQfsubZ5597124QQftidZ2QQtZkm

Bits & Bridles

• Training level to Second level must use a regular snaffle bridle
• Third and Fourth level optional use of a double bridle
• All FEI upper level tests require a double bridle with normal or crank nose band
• FEI Junior preliminary level test has optional use of double or snaffle bridle
• FEI test for 4, 5, and 6 year-olds require use of the snaffle bridle
• Be sure and check nose band rules if you are not using a normal, flash, or drop nose band
• Shank on curb bit my not exceed 10cm
• Flexible rubber bits are not allowed
• No side reins, martingales, breastplates, or other gadgets (like rein-aids) are allowed.
• Please check USEF or FEI rule books for images of the legal bits (they change often): USEF.org 

Don't forget to take your polo wraps or boots off your horse before you go in the ring I know more riders at every level that have been disqualified for this little mistake than almost any other.

If you are in doubt go ask a steward or call USEF (they are nice people) and read your current rule book!!