Include content created through InDesign/RoboHelp Is there a way to display content under a Drupal site/url that is not managed by Drupal? 

Specifically, we have a large manual (1700 pages) that is managed with Adobe InDesign which is used to create a printed version, one large PDF version, PDF versions of each chapter, and also an HTML version of the manual via RoboHelp. Because of the printing requirements, this is not content that we plan to migrate into Drupal (but we still need to display it on/through the site).

Example: Here is the page for the manual. You can see links for the Complete PDF and individual PDF chapters (which we would probably manage as Media - TBD). The question revolves around the HTML version of the manual. As you can see, at this point we have pretty much jumped out of the container of the hosting site (SharePoint), and are now displaying just the pure, rendered HTML that was generated out of InDesign/RoboHelp.

The content is updated annually and we have requirements to archive each version so that it is still accessible. Our current process makes it fairly easy because of the way that the /Manuals_HTML1 folder is excluded from SharePoint so we just make a copy of the content and give it a new folder based on the year. 

So, it doesn't appear to make sense to include this as actual content in Drupal. It feels like it would be some sort of exclusion within Drupal that essentially sends it outside of Drupal. Maybe a mod_rewrite solution?

Brand new to Drupal and currently in a week-long training. Definitely learning tons about how to handle the rest of the site, but this one is an open item.
Looks like the correct term is HTML or static microsite. These can be managed via .htaccess as seen in Maintaining a static microsite alongside Drupal's docroot.