Text layout is a loose hierarchy of segmentation
I love text layout, and have been working with it in one form or other for over 35 years. Yet, knowledge about it is quite arcane. I don’t believe there is a single place where it’s all properly written down. I have some explanation for that: while basic text layout is very important for UI, games, and other contexts, a lot of the “professional” needs around text layout are embedded in much more complicated systems such as Microsoft Word or a modern Web browser.
Source: raphlinus.github.io