# Comment Header Its helpful to include details about the code you wrote in a comment header. That way if you come back in a few months or years later to either reuse or make changes you can remember exactly what the code you wrote does. ```arduino /* Title: Control Relays with Nextion HMI Written By: (Place your name here) Date: 03/11/2023 Description: This code can read messages from the Nextion HMI over serial. The code will then turn these messages into commands for the Arduino Nano Every to perfrom. Thus turning on or off the 2 relays based on the state of the switch widgets on the HMI. */ ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://brlabelectronics.gitbook.io/tutorials-1/control-relays-with-the-nextion-hmi-and-arduino/nano-every-code/writing-the-code/comment-header.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.