From the Article:
"Reuters photographers, staff and freelance, must not stage or re-enact news events. They may not direct the subjects of their images or add, remove or move objects on a news assignment. Our news photography must depict reality. Any attempt to alter that reality constitutes fabrication and can lead to disciplinary action, including dismissal."
I guess Joe Rosenthal would have been fired for his famed flag raising on Iwo Jima photo!
http://www.iwojima.com/raising/raisingb.htm