Inner steering arm fail...

That would depend upon which side of the vehicle the worn track rod is on for me!

Once I exit the drivers door with the engine idling I gently operate the steering wheel leftwards and rightwards to see the drivers road wheel moving. I then slow the movement of the steering wheel to see just a slight movement and at the same time by feel try to experience if play/wear can be detected at the steering wheel. If I can experience it then subjectively I try to establish if 13 mm or more free play is present, and then using [2.3.a] make an informed decision.

However, the same cannot be said for the nearside of vehicles as the tester is unable to see that free play/wear at the road wheel, which then must be decided by the tester as to whether the vehicle is in such a dangerous condition that the test might have to be abandoned, or something like a brake test would be considered dangerous to the condition of the vehicle and again refuse to brake test that said axle. 

Obviously I can't comment on your typical case, but I've seen these track rods with 5 mm or more wear in them and truthfully they are knackered but I've never refused to brake test or abandon the test because of them. I've never seen any evidence to suggest they actually fail in service and are a threat to road safety.

The reason I asked is that the instruction from on high is that an inner steering arm cannot be failed, it ann only be advised as you cannot - unless the boot has gone- see the inner joint in question, it can only be advised or dangerous advise.

When in training I was told you can fail the joint. The treads are too fine to introduce a play to a significant extent. but can be a source of play if the joint is not tight to the rack.

thx guys for the replies. Its not really black and white.

Ive been instructed from now on to advise only on this particular failure. it at best will be down at best as a dangerous advisory, This if your not aware is not a failure in its own right even as dangerous.
so because it still produces a pass, the work in most cases is unlikely to be done as its 'do the failures only' not the advisories type of place and customer.

Even tho there is significant ( 3-4mm ) of wheel play.

I failed the car on 2.1.3.b 1.

I had this on the Joey s dad's mondeo last week advice play steering rack ends Rack boot s insecure ( water had got in and they perished ) repaired properly new rack ends and boots last night I tracked it up first thing then a retest and road test ! Once removed you could see the play in them

I may be stating an unpopular opinion, but from DVSA's instructions it is simply black and white. The joint itself is not to be failed, it's that simple. There is the failure for play at the steering wheel, but as Dynamo has already pointed our, that only works for play in the offside joint. That is our instruction from on high. People will find their way around this, and in my opinion, rightly so. However, when someone specifically asks the question, then that should be made plain, before discussing what we do in the real world where people die from worn parts.

I had a KIA in last week both rack ends Donald ducked no play at the wheel so manual advise with a dangerous tacked on.
Not a testable item according to the manual but if a track rod end had half that much movement it would fail.
But what do we know !