They are divided into the following four sub-families:
They are commonly used for elevated and highly elegant designs and are certainly unusable for long body copy.
Almost all the aforementioned families are proportional in their style, (each character takes up space that is proportional to its width). This sub-family addresses each character width as the same, with narrower ones, such as i, just gain white space around them, sometimes resulting in weird appearances. Hence, Due to their nature and their spacing, they aren't advised as copy typefaces, since their mono spacing can bring unwanted visual imbalance to the text.
Recently even Blackletters (the very first fonts designed with the very first, physical printing machines) are being named under this category.