Acrolinx works best with the XML Editor. So, it's a good idea to use the XML Editor to edit and check your content.
What You Can Check
Acrolinx for MadCap Flare can check the following filetypes:
|Flare HTML Document||*.htm, *.html, *.xhtml|
What Acrolinx Includes in Your Check
Sometimes, Acrolinx will highlight an issue that contains multiple tag types. Acrolinx doesn't support mixed tag text like this. Cards where the highlighted text contains multiple tag types become grayed out when you click on them.