During January 2026, Guiju focused on enhancing Unicode ligature documentation within the rust-lang/rust repository. They improved guidance for the to_uppercase and to_lowercase functions by clarifying code-point mappings and updating examples to better reflect Unicode standards. Using Rust and leveraging expertise in Unicode handling and character encoding, Guiju replaced outdated examples, such as the ß to SS mapping, and clarified that 'ffi' is a single code point mapping to 'FFI'. By switching the ligature example to 'ſt' for visual accuracy, their documentation changes provided clearer onboarding and reference material, demonstrating careful attention to detail and depth in technical communication.