word_separated_natural_casing_is_the_GOAT

Try it. You will not regret it.

Specifically, the rules are:

• Use your language's non-alphanumeric "separator" character in your identifiers!
  • If your language doesn't have such a character, go away.
• Stop forcing yourself to case words-within-identifiers unnaturally!

For example:

• WordSeparatedNaturalCasingIsTheGoat (PascalCase) Dumb.
• wordSeparatedNaturalCasingIsTheGoat (camelCase) Not better.
• word_separated_natural_casing_is_the_goat (snake_case) Almost there.
• word_separated_natural_casing_is_the_GOAT YESSSS!!!

Some languages may have environments with constraints you have to accommodate (or even exploit). For example, in Roslyn C#, the compiler warns against using a type identifier that starts with a lower-case letter. That's fine, you can simply always upper-case that first letter of a type identifier. This has a thin silver lining; if a nested type's natural name starts with a lower-case letter, then a member in the containing type can have that natural name as its identifier without provoking a compiler error.

In over a decade (and still going) of experience dealing with many casing styles in a complex STEM domain, word-separated natural casing is by far the most readable casing style I've encountered. Especially in complex domains where acronyms are plentiful and also valuable for conveying necessary meaning.