The "Dressy Casual" Designation on an Invitation

On an invitation it reads "dressy casual" or some such oxymoronic phrase that confuses more than it helps. Man, I hate that.

I appreciate your invitation
But "dressy casual" causes frustration
Tennis shoes and a dress?
Clamdiggers with a vest?
I would have dressed fine, but now, hesitation.

Those Who Don't Respond to an Invitation

Not responding to invitations, both formal (e.g. wedding invitation with reply card) and informal (Evite, email, phone call). L.F.

I invited you
You too busy to respond?
Next time, you can't come