Variable name length should match scope. A variable that only does something for three lines can be a single letter (Ex: i). A variable that is (god forbid) global should be nice and long (Ex: global_map_of_all_callback_functions). Everything I control should be readable.<p>Method/Class name length should be inversely proportional to usage. If it's used everywhere it should be convenient to type (Ex: add). Of course the method/Class should still describe what SINGLE responsibility the piece of code has. Remember that the name of the class & parameters is part of the method's call signature is many languages (Ex: Registry.add(Person person) could be read as "add person to registry").<p>Use the generally accepted standards of the community you code in. (Ex: Rust prefers snake_case and SCREAMING_SNAKE_CASE for names)<p>Be consistent.<p>Follow the principles of Clean Code. <a href="https://cleancoders.com/" rel="nofollow">https://cleancoders.com/</a><p>There's more, but that's the general thrust of it.