There is a device made of Silicone,that Women can use to write their name in the Snow,It's called a SheWee
I first head of those a few years ago, Richlacal, and every year when we winter camp, and every time a get a not so comfortably placed mosquito bite, I wish I had one. You guys can use a well sealed, well labeled bottle in the tent right? That could have it's advantages.