ICONS Infocom: Kofax Power PDF Training Video: Redaction
PDF files often contain sensitive information about products, organizations, or people that needs to be protected before sharing or publishing. This is usually done by redacting (or blacking out) the words or phrases that need to be protected.
Power PDF provides a variety of redaction methods. You can manually mark areas or use the easy search capabilities that lets you find any phrases that you would like to redact.