Power PDF provides you with powerful commenting tools to allow collaborative reviewing and commenting of documents. These tools can be found in the Comment Ribbon and comments in the current document are summarized in table form in the Comments panel, now located on the left in the Panel bar
The Comment ribbon contains two groups: Annotations and Comment Processing. All the presented items in the group Annotations become comments, and appear in the Comments panel, where they can be processed.
Textual comments can be added as Notes that can be collapsed and expanded, as text in a Text Box or a Callout (a Text box with an arrow). Existing text in the PDF can be emphasized by a highlight or underline and text can also be crossed-out. Drawing Objects can be inserted; these function as comments and can accept a linked note that can explain the purpose of the drawn shape. Active Markup allows proposed changes (insertions, deletions, attribute changes) to be marked for later review. Stamps can be placed in documents from the Stamps panel; these also appear as comments.
Comments do not become an integral part of the PDF, but can be replied to, commented and managed using the Comments Panel. Comments can be removed by flattening a document or Removing Document Elements.