No panty friday. This tradition includes both men and women of all ages. (For boys, this DOES include boxers). If a person goes commando more than just fridays, feel free to substitute the F with other days of the week. This is not to be confused with NCS (no clothes saturday).
"You're NPF today, right??"
"ummm, I'm wearing a skirt. Of course I'm wearing panties"
"But today is friday..."
"Today is friday? Oh my gosh, give me 30 seconds. I'll be right back!"