In one of my previous articles, Using Heading Elements to Create a Document Outline, I explained the importance of having valid outlines in an HTML page. The outline for an HTML document shows the structure of the content on the page. This is useful for user agents, who can use the outline to create, for example, a table of contents for the document. This can then be used by screen readers to help
![Document Outlines in HTML 5.1 | bitsofcode](https://cdn-ak-scissors.b.st-hatena.com/image/square/f8174882ea725b04e0e067f0051b0d22f7309873/height=288;version=1;width=512/https%3A%2F%2Fbitsofco.de%2Fassets%2Ficons%2Ficon_128.png%3Fv%3D05153cb11d)