Cleared for an approach - Can you descend and when?
Let's say you are flying at 5000' or descending to 5000' on a STAR.
Controller says: "You are cleared for an ILS approach" (it can be any type of approach).
You take a look at the chart and notice that the published approach altitude is 3000' (both IAF and FAF are at 3000').
1) Can you stay at 5000' and intercept the glide from there?
2) Do you have a right to descend to 3000'?
3) Do you have to descend to 3000'?
Local regulations may differ from country to country.
I am seeking a general world-wide rule that could be proven by legal document.
Please ONLY reply with a reference to an ICAO document.