The linked A+E thing is called a ligature:

https://en.wikipedia.org/wiki/Ligature_(writing)

Same root as "ligament" and "ligand."

It's a ligature in modern English, but it's a proper letter in Anglo-Saxon.

Ligatures or contextual letter variants (such as s being written with a different symbol when it's at the end of a word) are a sin to encode as characters. They should be part of the presentation layer, not the content layer! And don't even get me started on OCR which thinks such things are good to "preserve".