Worked on improving modem subsystem documentation within the zephyrproject-rtos/zephyr and renesas/zephyr repositories, focusing on clarifying command interface semantics and enhancing data parsing explanations. Used C programming and embedded systems expertise to update comments, ensuring accurate reflection of return values and parsing behavior in the modem command handler. Addressed documentation readability by refining comment placement and fixing typographical errors, which improved clarity and professionalism for both developers and users. These targeted documentation changes reduced ambiguity in the API, streamlined onboarding for new contributors, and contributed to the maintainability of the modem driver stack across both Zephyr repositories.