Use snake_case

ABAP is case insensitive which is why we recommend following the convention to use snake_case consistently.

There’s a character limit for names, e.g. 30 characters for methods. When you reach the maximum length of an object, don’t fall back to using flatcase or UPPERCASE. Try to conscientiously use abbreviations instead (see Use same abbreviations everywhere).

" a variable which contains the maximum reponse time measured in milliseconds
DATA max_response_time_in_millisec TYPE i.

is better than

" anti-pattern
DATA maxresponsetimeinmilliseconds TYPE i.