Dress Casual

Dear SJG,
The invite said:  Dress Casual.  So, I put my evening gown aside, my diamond tiara, my faux mink stole, my shiny party shoes, and selected something Casual.  'Cuz the invite said:  Dress Casual.  I'm a rule follower.  If an invite says:  Dress Like a 'Ho, out of respect to the hosts, I'll dress like a 'Ho.  But if the invite says:  Dress Casual, I will do just that.  Dress Casual.  Even though grammatically, I should Dress Casually.  The invite said:  Dress Casual.  So that's what I did.  Nice jeans, pretty top, ankle boots.  I thought I'd achieved the afore-mentioned Casual Look.  I showed up at the party feeling good about my fashion choices.  Until the hostess opened the door looking anything but casual. She had ignored her own directive.  She was all sparkly and glittery, all primed for New Year's Eve when it was just supposed to be... what's the word I'm searching for... casual.  I thought, okay, fine, she's the party-thower, she needs to look better than the guests.  I get it.  But the other female attendees had also ignored the "mandatory" dress code.  They were all sparkly and glittery, too, whereas I, on the other hand, was not.  As for the men, they got the memo.  They were casual.  But so what?  They're men.  Men can get away with casual.  Women can't, especially not when they're alone in their casualness.  So I spent a miserable evening, cursing my casual self, feeling like the underdressed elephant in the room. How can I avoid this sort of humiliation in the future?
Signed,
Casually Enraged

Dear Enraged,
I'm absolutely mortified on your behalf.  I don't know how you even have the courage to show your face in public.  I think you might stay inside until the shame abates and the mean-spirited gossip about you quiets down.  The Dress Casual thing is one of the SJG's major pet peeves.  My best advice to you is to ignore any invite that tells you to Dress Casual.  I've come to the conclusion that Dress Casual means the exact opposite.  Whatever you do, don't dress Casual.  Just don't. Better you should err on the side of fancy.  Also important to ignore:  the whole "No Gifts" thing.  That's another sneaky misdirect.  "No Gifts" means the exact opposite. Always bring a gift, always, always, or you'll be the only cheap-ass who arrives empty-handed.
You're welcome,
The SJG