Help:Extension:Linter/missing-end-tag-in-heading/en

The missing-end-tag-in-heading error is when a is opened in a header, but not closed. To fix it, provide an appropriate closing tag. Fixing these issues is high priority because unclosed tags inside headings can affect the display of all of the content following the unclosed tag.

Example 1:

In example 1, the span needs to be closed by adding at the end, before the   markup.

Example 2:

In example 2, the HTML tag needs to be closed by adding  at the end.

See for an additional explanation of missing end tag errors and how to fix them.