Chainless foundation

Dear users, dear authors,
What is a chainless foundation and what is it used for?

With the foot-loop stitch, you skip the sometimes very long foundation chain of stitches and start working on the first row right away. For filet curtains, for example, you use this technique for the scalloped edges.
You work the next stitch out of the foot loop of the previous stitch. There are many tutorials that explain this step by step. Once you get the hang of it, it’s a great technique.

The foot loop cast-on allows you to increase several stitches at the end of a row.
To do this, insert the hook into the last stitch of the row, work a chain stitch (this is the foot loop), and then work the actual stitch
(i.e., a single crochet, a double crochet, or whatever the pattern calls for). For the next stitch, insert the hook into this foot loop, work a chain stitch (foot loop), and then work the actual stitch, and so on, until you’ve reached the required number of increases.