Some typographic elements, such as paragraph format, accents, parantheses, different typefaces, underline, uppercase letters etcetera, have a signal function. One way of making a distinction in a text is to use a slanted version of a typeface. Another possibility to emphasize a word or part of a text is to use the bold version of the typeface. Sometimes such characteristics immediately catch the eye. The best and most effective way to make a distinction or to add hierarchy in a text is to use a colored version of the typeface.
The basic shapes of the Latin alphabet have not changed substantially these past few centuries. Characters are characters. A is A and B is B. If an A does not look like an A it ceases to be a character. Every character is legible, if not, it is not a character anymore. Unreadable or illegible characters or typefaces do not exist. Characters are part of a dynamic typographic system. Typography is a controlled and restricted area in visual communication where the rules of readability and legibility are constantly subject to change.