My sewing motto is "All Burda -- All the Time". Of course, I use other patterns, but Burda is definitely my favorite. This skirt is why. It has what I call "The Invisible Casing". I'm sure some more experienced sewer has seen and used this treatment, but I've never seen anything like it. It certainly isn't used in any Big 4 pattern.
1 3/4 inch elastic is used in this treatment. It is sewn to the top edge of the facing before the facing is folded down. So the facing becomes the casing!
Next, the lining is sewn to the edge of the casing. All of the stitching is on the inside of the skirt. Nothing but a folded over edge is visible from the right side. Although the instructions didn't say so, I stitched in the ditch at the darts and side seams to hold the folded down facing/casing in place. This feature will never be seen by anyone but me because I suffer from NDW Syndrome (No Discernable Waist) and I never wear anything tucked in. Luckily, tucked in blouses are not in style (are they?). Even if they were, I wouldn't wear them.
I like using BWOF and Burda envelope patterns (and other independent companies) because I often learn new and different techniques in the process of making the garment. Each new garment is a learning experience.