What are common mistakes when using PHP tags in a forum post and how can they be avoided?

Common mistakes when using PHP tags in a forum post include forgetting to close the PHP tags properly, using short tags that may not be enabled on all servers, and mixing PHP tags with HTML code incorrectly. To avoid these issues, always make sure to properly open and close PHP tags, use the full `<?php ?>` tags instead of short tags, and separate PHP code from HTML code for better readability and maintainability.

&lt;?php
// Correct way to use PHP tags in a forum post
echo &quot;Hello, World!&quot;;
?&gt;