Exotic names for methods, constants, variables and fields - Bug or Feature?

Question

after some confusion in the comments to

• Is it safe to have 1 letter class names in PHP, e.g A, B, C

I thought I make into a question. According

Answer 1

From the official documentation:

The class name can be any valid label, provided it is not a PHP reserved word. A valid class name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thus: ^[a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*$.