Redaction or a reducted document is the one where sensitive information on the document is reducted with broad black strips so none of that text shows on the actual print. The process of redaction can be easily done from the tools option of word perfect word processor where you simply have to choose the text that needs to be reducted and it is black and out, the search and replace features help too.
This way flow of the document contained remains in only the portions you do not want to share remain hidden this process is regularly practice to protect, lawyer client privilege doctor patient privilege and many more. Many corporates use this method to ensure that their information is not passed on to any unwanted individual.
Confidential is a necessity about many aspects when you are sharing information or providing necessary eagle documents to a third party. Process of redaction needs to be easy and accessible in the word processor.
Post redaction you need to be able to save the same document in a format where it is difficult to access file in different format for the purpose of sharing. This also provides the layer of protection against any type of attempt to un-redact a document. So instead of sending in the same text format you can save the document in a PDF format or any other such format where in the receiver can read the document but the redacted part cannot be accessed.