Debbie Bliss baby trousers pattern help decrease and make up

I’m following a Debbie Bliss pattern making trousers for a baby.
I’m shaping for the legs. It says Dec 1 st at insidecedge of next row.
What is the inside edge?
It also says to make up, work a herringbone casing over rivet waist, enclosing elastic. What do they mean?
Thank you

Welcome to KnittingHelp!
I see two patterns on Ravelry. Which book is your from?
https://www.ravelry.com/patterns/search#sort=best&inline=&query=debbie%20bliss%20baby%20trousers

There’s a correction noted for one of the patterns that may apply to the legs.

The herringbone stitch is a sewing stitch that makes a kind of case or net over the elastic.

I don’t know what the pattern means by “rivet waist”. Some of the knitters just ran the elastic through the waistband, others depended on ribbing or a cord to hold the pants up.

Aah thank you. I’ve signed up to Ravelry. But I can’t see the pattern correction. Could you tell me how to find them? Thank you.

It’s a wonderful resource especially for patterns.
This pattern has a link to errata:

I’m not sure if this is the part of the pattern where you have a question. If this doesn’t help, you could quote a couple of rows from the pattern. Don’t give us a large portion of the pattern due to designer copyright.