There is are many things that were left out in the storyline in Halo. From the time of the first contact with the Covenant, to the time Reach Fell, and some gaps in between, many things have been cut out from the main story. Well, here, members can chronicle the events that happened in the time between. These can include major falls of planets to minor skirmishes between UNSC and Covenant.
All inventory and equipment are based on the time periods in which they were used.