There are four ways of escaping from HTML and entering "PHP code mode":
Example 5-1. Ways of escaping from HTML
The first way is only available if short tags have been enabled. This can be done via the short_tags() function, by enabling the short_open_tag configuration setting in the PHP config file, or by compiling PHP with the --enable-short-tags option to configure.
The fourth way is only available if ASP-style tags have been enabled using the asp_tags configuration setting.
Note: Support for ASP-style tags was added in 3.0.4.
The closing tag for the block will include the immediately trailing newline if one is present.