Ordo, you after my job? :grin:
BGB, Pg 29, Rapid Fire Weapons
"Any infantry model armed with a Rapid Fire weapon can shoot twice at targets up to 12" away"
The key word here is can. The model can shoot twice, not must. That is the rule right there in plain English and does not say you must shoot twice in any way, shape, or form. The summary does not, and never will, override or expand on the written rule. The fact is that the rule says you can shoot twice which means that you can choose not to. If you couldn't, the rule would say you must shoot twice.
A good example of this is the chaos dreadnought entry on pg40 of the new chaos codex under the Blood Rage rule where it says very plainly that it "must move as far as possible towards the nearest enemy". Must move, not can, meaning their is no choice to be made.
So again, the fact that a Rapid Fire weapon 'can' fire twice on the move up to 12" does not mean it must.