Final answer:
Security guards follow a set of documents called post orders, which dictate their duties and procedures at a specific site. These orders are integral to security and safety, guiding guards in routine and emergency situations.
Step-by-step explanation:
The set of documents that describes the duties that security guards working at a particular site must carry out and the procedures they must follow is known as that site's post orders. These documents are essential for maintaining the security and safety of the site, and they provide specific guidelines for routine and emergency situations. They are a crucial part of a guard's training and daily duties, ensuring that they perform their roles effectively and in accordance with the site's expectations and regulations.