Even if "crpm" is a contextually known entity, I'd consider "idxcrpm" a terrible identifier. a) it's two words without a clear boundary – "idx_crpm" would be b

Even if "crpm" is a contextually known entity, I'd consider "idxcrpm" a terrible identifier. a) it's two words without a clear boundary – "idx_crpm" would be better (or idxCrpm if your project uses camelCase) b) it's an unnecessary abbreviation – "index" is only two chars longer than "idx" and legibility trumps raw brevity c) it's grammatically incorrect (without the "into" preposition that you used), hindering legibility – gramatically correct would be "crpm_index" (or crpmIndex)