NewOneDrive · SharePoint · Web
OneDrive: Anchored comments in the PDF viewer
Anchored comments are being added to the PDF viewer in OneDrive and SharePoint on the web, enabling users to comment on specific spots and text in PDFs with replies and @mentions. This feature will be enabled by default with no admin configuration needed.
Microsoft's description
Microsoft is adding anchored comments to the PDF viewer in OneDrive and SharePoint on the web. Users can attach a comment to a specific spot on a page, to selected text, and collaborate through replies and @mentions — bringing PDF review to parity with commenting in Office documents. This feature will be on by default and requires no admin action.