The main element is an exact analogue of ARIA's role="main" , and is designed to show screenreaders and assistive technologies exactly where main content begins, so it can be a target for a "skip links" keyboard command, for example. It could also be used for content syndication (Instapaper-ish things); mobile browsers could zoom in on main when encountering non-responsive websites. It should therefore be used once per page. If you use something like <div id="main"> (or similar, such as <div id="content"> ), simply replace that with <main role="main"> .
In-text attribution is the attribution inside a sentence of material to its source, in addition to an inline citation after the sentence. In-text attribution should be used with direct speech (a source's words between quotation marks or as a block quotation ); indirect speech (a source's words modified without quotation marks); and close paraphrasing . It can also be used when loosely summarizing a source's position in your own words. It avoids inadvertent plagiarism and helps the reader see where a position is coming from. An inline citation should follow the attribution, usually at the end of the sentence or paragraph in question.