Vanity FairWomen's Briefs

The sizing information is based on waist size, but that doesn't seem helpful for underwear sizing. With a 39" hip, what size is best?

My recent question didn’t get a clear ansir. I have a size 7 in bikini in these. (30 n below waist) will 6 fit?

I have been buying 8/xl. the numbers on here say are in 16345. and then the other number is 13108. which is the style number? and is that an 8 regular

What is the RN code for these?