As a female in between a junior's size and a woman's size in jeans/pants, I would like to tell you what I know about the sizing.  I hope this helps everyone when buying and selling.

Juniors sizes are almost always ODD numbers--1,3,5,7,9,11, and 13

Women's sizes are almost always EVEN numbers--4,6,8,10, etc.

There are juniors sizes that say 9/10 or 11/12 in bottoms.

It can be confusing when looking at an auction that states an item is a juniors size 10. I understand that some brands or designers may not size the way the mainstream does, so it is always, always important that you put measurements on the auction when selling--all of them, not just the length. Also, be aware of sizes that are merely waist measurements- like designers overseas and more high-end brands.  I guess this is kind of a pet peeve of mine in sense.

Be sure the put the rise, inseam, length, waist size and even a thigh measurement when flat can help you have a better sale and a happier customer.