# Warnings that are probably less important.

Consider using the “h1” element as a top-level heading only \(all “h1” elements are treated as top-level headings by many screen readers and other tools\)\.
Document uses the Unicode Private Use Area\(s\), which should not be used in publicly exchanged documents\. \(Charmod C073\)
Section lacks heading\. Consider using “h2”-“h6” elements to add identifying headings to all sections, or else use a “div” element instead for any cases where no heading is needed\.

# Opinionated informational messages.

Self-closing tag syntax in text/html documents is widely discouraged; it’s unnecessary and interacts badly with other HTML features \(e\.g\., unquoted attribute values\)\. If you’re using a tool that injects self-closing tag syntax into all void elements, without any option to prevent it from doing so, then consider switching to a different tool\.