The essence of a dispute about specification is that it happens when Government discovers it is not getting what it thought it was going to get. If the expectations are wrong, the words of the specification will never be right. Even if the expectations are right, you may still have trouble with the words, but the single most important thing you can do is bring your stakeholders to complete agreement on what you are supposed to be procuring. If your stakeholders all have an input into the specification and they all want mutually incompatible things, then (surprise!) the specification will be inconsistent and disputes will follow. Your work on objectives and scope should have been effective in securing agreement among your stakeholders, but don’t take it for granted: things can look different when you drill down into the detail.