(to continue straying for a moment..) perhaps though it best depends on the variable specifics: like how often it appears, how far apart multiple uses are, etc.

(to continue straying for a moment..) perhaps though it best depends on the variable specifics: like how often it appears, how far apart multiple uses are, etc. Some natural limits might be: (1) single letters for extremely local terms whose structural meaning is more salient than denotation (canonical example: loop counter); (2) fully spelled-out terms for globally-significant terms (not necessarily in global scope) whose denotation is crucial (canonical example: an app configuration value). Even two short camel-cased words often seem unnecessarily verbose for a loop counter to me. Whereas an important global config variable might justify the full THIS_IS_WHAT_I_AM_FOR treatment.