137 | | PHP scripts should output HTML 4.01, not XHTML. XHTML isn't supported by many browsers. Serving XHTML with a text/html MIME type is not a solution either (it's not XHTML anymore, it becomes invalid HTML). |
| 137 | PHP scripts should output "HTML 4.01 Transitional". |
| 138 | The HTML should pass the [http://validator.w3.org/ W3C validator]. |
| 139 | This means, e.g., you must have quotes around attributes |
| 140 | that have non-alpha characters in them. |
| 141 | However, all-alpha attributes need not have quotes, |
| 142 | and tags like <br> and <p> need not be closed. |
| 143 | |
| 144 | The HTML need not be XHTML. |
| 145 | XHTML isn't supported by many browsers. |
| 146 | Serving XHTML with a text/html MIME type is not a solution either |
| 147 | (it's not XHTML anymore, it becomes invalid HTML). |