 <p>User-agents define the <code>&lt;a /&gt;</code> tag as interactive, but this element was only designed to make an hypertext reference without any idea of click.</p> <p>This user-agent behavior became a standard, which is not the same with the longdesc attribute of the <code>&lt;img /&gt;</code> tag.</p> <p>Because HTML was designed to structure information and contents, not to make interactions, the new version of HTML (5) tries to "palliate" this lack and introduces the <code>&lt;command /&gt;</code> tag to have interactions on HTML non-informative contents as "read more" anchors in example.</p> <p>Note that "A command can be explicitly part of a context menu or toolbar" should also say that the <code>&lt;command /&gt;</code> can be used in another context and does not require <code>&lt;form /&gt;</code> tag instead of <code>&lt;input /&gt;</code> or <code>&lt;button /&gt;</code>.</p> <p><sub>Thank you to Spontifixus &amp; Daniel Kutik for correcting this answer</sub></p>