A redaction annotation (PDF 1.7) identifies content that is intended to be removed from the document. The intent of redaction annotations is to enable the following: a)Content identification. A user applies redact annotations that specify the pieces or regions of content that should be removed. Up until the next step is performed, the user can see, move and redefine these annotations. b)Content removal. The user instructs the viewer application to apply the redact annotations, after which the content in the area specified by the redact annotations is removed. In the removed content's place, some marking appears to indicate the area has been redacted. Also, the redact annotations are removed from the PDF document. Redaction annotations provide a mechanism for the first step in the redaction process (content identification). This allows content to be marked for redaction in a non-destructive way, thus enabling a review process for evaluating potential redactions prior to removing the specified content. Redaction annotations shall provide enough information to be used in the second phase of the redaction process (content removal). This phase is application-specific and requires the conforming reader to remove all content identified by the redaction annotation, as well as the annotation itself. Conforming readers that support redaction annotations shall provide a mechanism for applying content removal, and they shall remove all traces of the specified content. If a portion of an image is contained in a redaction region, that portion of the image data shall be destroyed; clipping or image masks shall not be used to hide that data. Such conforming readers shall also be diligent in their consideration of all content that can exist in a PDF document, including XML Forms Architecture (XFA) content and Extensible Metadata Platform (XMP) content.