These were mentioned but not linked to in the previous form of the article/blog, had a quick look at the newer version you linked to and that may still be the case.
A lot of the Awk info I had found prior to stumbling on these articles was focused on command line one-liners. So the sections on defining Awk scripts as files and multiline records were a great help to me.
https://developer.ibm.com/tutorials/l-awk2/ https://developer.ibm.com/tutorials/l-awk3/
These were mentioned but not linked to in the previous form of the article/blog, had a quick look at the newer version you linked to and that may still be the case.
A lot of the Awk info I had found prior to stumbling on these articles was focused on command line one-liners. So the sections on defining Awk scripts as files and multiline records were a great help to me.