Lyra's ball dress code enforced?

I'm gonna be going to Lyra's ball for the first time this year and I'm looking to find out if the dresscode for lyra's ball that's posted on the website is enforced at all. I'm mainly wanting to know if the rule about skirt length is enforced, but any other info on the strictness of lyra's ball would be great as I'm trying to find an outfit for attending.