Redaction is the process of obscuring information that cannot be disclosed under the Freedom of Information Act 1991 by:

• blocking out individual words, sentences or paragraphs or
• removing sections or whole pages

from a document prior to its release or publication.

There are a number of redaction methods either manually or electronically.

Hardcopy documents

Manually redacting information techniques includes:

• cover-up
• white/black out
• physical removal.

Whichever method is used, the end result must ensure that the text that has been removed from the document cannot be seen or ‘guessed’ by the reader.

This means ensuring that the text in the document is sufficiently obscured so that it cannot be deciphered. In some cases it may be important to block out content on either side of the exempt information to ensure that the original text cannot be discovered.

Regardless of the method used, redaction must always be carried out on a copy (be it physical or digital), leaving the original document intact.

Softcopy documents

Documents may be redacted electronically in their original format (eg MS Word) using deletion tools. However, agencies must exercise caution if using this method. It is possible that deleted information may still be recoverable because there is a potential for information to remain hidden within non-displayable portions of the document.

In addition, converting an MS Word document to Adobe Portable Document Format (PDF) does not automatically remove all of the document’s metadata. (Metadata is the information about the document, eg file name / document creator / corrections made).

Digital documents that have not been redacted using specific redaction software, should only ever be provided in hardcopy format. However, if the redacted copy is required in an electronic format, agencies could use a scanner to scan a hardcopy of the redacted document into an appropriate format, such as PDF, and provide the applicant with a PDF version of the document.

Redaction software

Effective electronic redaction requires the actual removal of the text or image data from the electronic record. That is, the text and images are completely removed from the document to ensure the information cannot be recovered.

Some redaction software can be customised to print the FOI exemption clause, used to refuse access, in the space where the information was removed.

If agencies wish to use redaction software they should seek advice from the appropriate Information Technology personnel in their agency.