Instead of "kep", if you want something that visually stands out, there are also lots of fun little symbol-like characters you can use, even when you're dealing with a language where identifiers are limited to ID_Start/ID_Continue (e.g. Javascript, Rust). My favorite collection :)

  ⴵ ⵛ ꘜ ⵣ ꕤ ꖜ 
  ꘖ ꧮ ⴲ Ⰴ Ⰺ