Can you show me the rule that was never written?
Which rule would that be?
No one has said it was a rule. There is no exact to any wedding, just respect to the couple and to their traditions (family, heritage, culture, etc.) Traditions, etiquette, etc are not rules just guidelines of things that have been handed down.
Be unique and create your own traditions. Amaze your clients, stand out, do something different. Todays brides will appreciate that. I've had brides that have told me "I just want my guest to have fun. Let them dance whenever they want". I've also had venues who get upset when guests dance during dinner. Sometimes you just can't stop the music. But just so you know I presented no "false" statements. As you can see below, many people believe in the old traditions of the Bride and Groom are the ones to open the dancing at their wedding. The bride and grooms first dance is to be done before the guests dance. That's way I find it best to do this early on in the evening.
The Wedding Dance
Dancing at your reception is a lovely way to bring an air of elegance and family togetherness to a wonderfully happy and joyous occasion.
Traditionally, the bride and groom will be the first to dance as their special song is played softly. Lights dimmed low create a romantic atmosphere.
http://www.ourmarriage.com/html/the_wedding_dance.html
Dance Etiquette
The band or disc jockey will probably lead you during the reception by inviting various family members onto the dance floor, but it helps to know a little wedding reception dance etiquette in advance.
The bride and groom always have the first dance, which typically takes place after the initial announcements and speeches. Your DJ will invite you to the floor. The father of the bride will cut into the dance at some point, probably after a number of guests have snapped pictures of this very sweet moment. The groom graciously places the bride's hand into her father's hand; then the groom asks the bride's mother for a dance.
http://www.weddingclipart.com/guide/wedding-receptions/wedding-reception-dance.html
Can you give us a general timetable for all of the traditional reception rituals?
Q: My fiancé and I want to include all of the traditional rituals at our wedding reception. When should the special dances, the best man's toast, and the bouquet and garter tosses take place? —Salinas, California
A: Since you want to make sure that you don't forget any significant activity at your reception, it's a good idea to plan ahead. In fact, at least a week or two before your wedding, finalize a reception schedule of events with your maitre d", bandleader and wedding consultant (if you have one) so that all are aware of your arrangements and can plan accordingly.
Let's start with the special dances:
The first dance between the bride and groom kicks off the dancing at the beginning of the reception, just after the wedding party has been announced (although you may also wait until after the meal has been served). Guests gather around as the couple dance to "their" song. The master of ceremonies or band leader will then ask your parents, your fiancé's parents and the rest of the wedding party to join in. Finally, the guests may also be invited onto the dance floor.
http://www.bridalguide.com/etiquette-tradition/article.cfm?aID=992#RITUALORDER
Here's one from the UK:
If there was to be dancing, the bride and groom would lead the first dance with the best man and chief bridesmaid joining in half-way through. Finally, the bride and groom used always to leave before their guests, having first changed into their going-away outfits. Just before leaving, the bride would turn her back on the group and throw her bouquet over her shoulder. The single female who caught it would be the next bride.
http://www.howtobooks.co.uk/family/weddings/reception.asp