This section is fairly self-explanatory (hence the length). Opera lets you choose your own font for various pieces of the user interface (such as the compose font for email) and web pages. Note that “interface display email” is also used for newsgroups (Usenet) and newsfeeds (RSS and Atom) as well.
It can be a good idea to set a minimum font size. Opera attempts to display fonts no smaller than that size. This is very useful when visiting pages designed by youngsters with perfect eyesight. (<q class="grumpy-old-man">you little whippersnappers with your perfect eyesight and your danged loud rock & roll music.</q> *shakes cane menacingly*)
See also and .