How can the $_GET variable be integrated into a form tag in PHP?

To integrate the $_GET variable into a form tag in PHP, you can set the form action attribute to the current PHP file and append the desired $_GET parameters to the URL. This allows the form data to be submitted to the same PHP file with the specified $_GET parameters included.

<form action="<?php echo $_SERVER['PHP_SELF'].'?param1=value1&param2=value2'; ?>" method="GET">
  <!-- Form fields go here -->
  <input type="submit" value="Submit">
</form>