What are the best practices for organizing and documenting changes made to PHP code for easier future reference?

When making changes to PHP code, it is important to organize and document these changes properly for easier future reference. One best practice is to use version control systems like Git to track changes and provide a history of modifications. Additionally, using clear and descriptive commit messages can help others understand the purpose of each change. It is also helpful to maintain a separate documentation file or inline comments within the code to explain the changes made.

// Example of organizing and documenting changes in PHP code

// Function to calculate the square of a number
function calculateSquare($num) {
    // Add comment to explain the purpose of the function
    // Also, mention any recent changes made to the function
    // Updated calculation method based on feedback
    return $num * $num;
}