Note that ASP code support is simply limited to preserving anything between tags.
Select x/html + ASP if you want to compress x/html containing ASP code. Only the following tags are considered valid open and close tags. With this option you can safely minimize the x/html code of a Wordpress theme, a Joomla template, a Drupal template or any other PHP based template. This will ensure that your PHP code remains intact while your x/html code gets minimized. Select x/html + PHP if you want to compress x/html containing PHP code.
Select x/html for web documents that do not contain server side code, such as static web pages. CSS code contained between and tags is considered x/html with embedded CSS code.