It's how Battlefield2 is meant to be played and the 21CW Mod introduces several changes and modifications to the gameplay of Battlefield2 specifically for the Australian Allied Forces tournament. Among some of the changes are:

~Selectable rounds for helo gunners, Stingers for those pesky fast movers.
~Miniguns added to the Opposition transport helos
~Selectable Main Battle Tank rounds (SABOT and HEAT)
~Changes to the kits and classes to include weaponry in other classes that are not available in normal BF2
~Improved attack helo physics and flying
~Improved capabilities and speed of the transport ground vehicles
~Laser-dot crosshairs
~Zoomable stationary machine guns
~Reduced jump height and increased stamina used in jumping to remove bunny hop exploit

AND MUCH MORE... every aspect of every weapon, vehicle, and class was looked at and tweaked to some degree.

The 21CW Mod will be run by the 21CW Australian Allied Forces tournament, which everyone is invited to join at http://www.AustralianAlliedForces.com (Details of server IP in forum.)

“Soldiers, as part of the Australian Allied Forces, you will be expected to work as a team to achieve one goal .As a part of any Army it is mandatory that all soldiers go through boot camp, on completion of Boot camp you will be issued the rank of Private. You will be placed into either the 3rd Royal Australian Regiment or the 6th Afghan Kandak in battle. Assisting your Regiment and company on all levels with intelligence reports and any other extra requirements, will not only help your Regiment and the Tournament as a whole to be successful in battle, it will help you achieve higher ranks within the Tournament! Ranks will be awarded to those soldiers who prove themselves both on and off the battle grounds. We live, breath and fight together soldier. Those who fight together, go home together. Enlist today, Soldier!”
Welcome to what we call 21st Century Warfare Australian Allied Forces. AAF is a mod based on the already successful 21st Century Warfare (www.21cwmod.net).
When taking part in the Tournament, you will follow through an Australian Military Chain of Command and simulate real wars against the Afghanistan Forces. You will play as either allied or opposition and you will be expected to follow any instructions given by your leaders without any disputes. We do not tolerate 'Rambos' or 'Team-killing'. You will in return have fun, be apart of a world wide community and play the game the way it was meant to be played.
Welcome once again Soldiers to Australian Allied Forces, 21st Century Warfare!
Join your fellow Soldiers who have experienced 21CW and found the right way to play Battlefield2.

Note. A new patch has been released for the 21CW Mod called 21CWMOD_1.0.3_Patch.exe. This patch is also required.