Interesting, I didn't know that pydoc supports this.

Specifying all possible prefixes is cumbersome and errorprone. The number of combinations grows exponentially with adding new letters. I suggest either to specify only lower-case variants and generate all variants with upper-case letters (as it done in the tokenize module) or always calls the lower() method when look up in the symbols dictionary.

It may be worth to add a special topic for f-strings.