Dear friends, we love your children... but our families are quite large as it is and we cannot possibly accommodate all the littles. We invite you to enjoy this night as a night off- a time to celebrate, eat, drink, and dance to your heart's content.
If we have indicated a "+ guest" on your invitation, we have accounted for the loved one we know and are happy to have him/her join us.
Cocktail/ formal. It's not a code, so much as a suggestion. Dress as fancy as you'd like, but keep in mind, we hope to dance with you at some point in the evening, so plan your shoes accordingly!