Revision histories and metadata
COMMON ERRORS WITH REDACTING INFORMATION
A common error in redacting information is to use the wrong method to redact the electronic file.
Below is a partial list of misconceptions and methods NOT to use:
< Changing the text’s font to white will make it look as though the words disappear, but they
don't! The metadata that remains can be used by tech savvy individuals to reveal the hidden
text you were attempting to redact.
< All word-processing programs (such as Microsoft Word, Corel WordPerfect, WordStar, etc.)
retain a lot of hidden code (called "metadata") that can contain revision history and other
information. This metadata can reveal anything that was contained in the file at any time,
even text that was previously deleted or changed, and even if the file was re-saved. This is a
useful tool for tracking revisions, but if this information is not purged from the document,
anyone can view this information, even after it has been converted to PDF.