Thank you very much to everyone for the good replies.
I would agree with Radarman that if "Hold short" was clearly defined I would not ask that question.
I am a pilot and myself I have never had any doubts where I should stop if I got such a clearance, I would always use the holding point or other appropriate markings. I should say I have never seen in Europe any other pilot crossing holding point markings to hold short of the runway.
I am in China now. I have seen that a lot of planes when get the clearance to hold short of the RW proceed beyond the holding points markings. After that we had the discussion with one of my colleagues and he said that he would do the same as others did.
Part V, 10.3 seems quite specific saying that: "aircraft shall not be held closer to the runway-in-use than at a runway-holding position"
Obviously if any plane goes beyond the holding point and enters critical ILS area will induce some interference for arriving aircraft. That might be ok in CAVOK but not in bad weather. And as we can see from the definition of "Hold Short" it has no reference to weather.