Secondary information is that which was recorded by someone not present at the time of the event, or, recorded after the event took place. I caution you to remember that either primary or secondary documents may contain errors. As an example, lets consider a passport in particular my passport. I have kept my passport current for many years so that I am able to travel abroad whenever the possibility presents itself. To receive a passport, one must present a current picture, birth record, and properly filled-out passport application form.
Passports are valid for a period of ten years and are easily renewed with the proper identification.
A traveler presents the passport to the customs official before leaving and upon entering another country for an official time-dated stamp affixed to the document. Therefore, since the document is stamped at the time the passport holder appears before the customs agent, passports are considered a primary document. On 17 April 1999, I entered the Republic of South Africa at the Johannesburg International Airport. My passport was officially and accurately stamped that day by the Passport Control official on duty. When I departed Johannesburg on 25 April on flight SAA 203 for Miami, Florida, my passport was again stamped.