PHP - Procedural Scripts

As noted in the section outlining Comments & External Documentation, each file should begin with a block comment detailing important information about the file. In addition to the information outlined in the previous section, you should also include the following information:
- Any classes that were used in the script
- Any external files that were included using the include, include_once, require, or require_once functions.
- A list of functions and a brief description of what each does.
- If the page produces HTML output, be sure to include information about any client-side files that are included (i.e., JavaScript, CSS, etc.)1)
Constants should be defined at the beginning of the file.
Any included files should be included after declaring constants.
Any functions should be present after including any external files.
All procedural code should be present after all functions have been declared and coded.

1) It should be noted that any HTML produced by a PHP script should adhere to the HTML standards.