Commenting in Adobe Reader X
One of the highlights for the release of Adobe Reader X back in October 2010 – amongst many – was that the Sticky Note tool and the Highlight tool are now always available for any PDF file: as long the document permissions allowed for commenting. But those are not the only commenting tools and functionality available in Adobe Reader X. In fact, the software has many more. But those capabilities are only made available when the PDF file being viewed in Adobe Reader X has been enabled for additional functionality using Adobe Acrobat X Pro (choose File > Save as > Reader Extended PDF) or Adobe LiveCycle Reader Extensions.