What is "official documentation"?

Some private security credentials require the submittal of official documentation for the purpose of eligibility.  This refers to personnel records; DD214; copies of business licenses indicating ownership; law enforcement transcripts; certificates of training completion; a signed letter provided directly by a current/previous employer detailing dates of employment and job duties; college transcripts; letters of commendation; private security services registrations; certifications, and/or licenses from other states; and/or other employment, training, or experience verification documents. A resume is not considered official documentation.