Rex,

Taken from a post elsewhere and shortened (Hat Tip to Tukhachevskii).

Col. Richard Kemp & Chris Hughes, Attack State Red.
The book follows the exploits of the 1st Battalion The Royal Anglian Regiment Battle Group (also attached were an Estonian Armoured Infantry Company and a Danish Reconnaissance Company) during their six month tour in Helmand province’s Sangin Valley in spring 2007.

Maj. Mick Aston talking in an Army Air Corps WAH-64...
The JTAC said to Aston, “He repeats what he told us before, he cannot fire until he has positively identified the target”. Fuming, Aston replied, “Well I have PID’d the target. The Viking crews have PID’d the target. 7 Platoon has. How much more PIDing does he need?”. “Sir, he says he needs to PID it himself before he can engage”. “Look I used to be in a helicopter recce squadron. I know how difficult it is to identify people from the air if they are well concealed, even with the kind of kit these fellas up there have nowadays. But we’re firing at the enemy, the Apache pilot can see our tracer. The enemy’s firing back at us, the pilot can see their tracer too. What is the problem?” [...] “What is he bothered about? Is it civvies in the area? There aren’t any. But if there had been, we’d have killed them all by now with our guns”.[...]Aston was raging. He refused to believe the Apaches had to work under such a ridiculous constraint – in this situation.[...] He said, “Let’s get rid of him now. We’ll get something else on to it. Tell the pilot – repeat these words to him exactly from me – fire at the target now or get out”.[...] Aston turned to Corporal Wilsher, his mortar fire controller. “The minute the Apache clears the airspace start engaging with mortars. I want HE up and down that treeline. Can you do that, or will the mortar line commander need to [...] do some PIDing in person?” He turned back to the JTAC. “While he’s doing that, get me some proper close air support”.(p.65)
I know that we've had more current posts on ROE, CAS and criticism on other threads. One hopes the UK position has improved since 2007, to be fair elsewhere in the book the authors report praise for US CAS.