A photograph of the back page of a Christchurch City Council form. The form allowed contractors to apply for the authorisation to enter the Christchurch Red Zone after the 22 February 2011 earthquake. Information on the back reads, "What does this authorisation mean for me? I am wearing appropriate personal protection clothing and equipment. At all times DO NOT enter any red placarded building. You may enter a yellow placarded building for a period of time (no longer than 30 minutes) and follow the instruction of the escorts. A green placarded building may be accessed for longer periods. Please note: do not enter any buildings which are not for the purpose of your authorisation".