When this option is checked, all embedded HTML markup will be filtered out and not appear in the generated output. If unchecked everything gets into output as it is.
Note: This setting affects only output of those template components whose 'Render embedded HTML' option is checked. This option is located at the component's Properties Dialog | Formatting | Text Flow tab. When such an option is not specified, any markup contained in the component's output will be treated as an ordinary text.