Just read the charts and follow the instructions, its crystal clear. Who cares if its different to everywhere else, its there for a reason particular to that area. Its the same as not receiving your Atlantic crossing clearance from Shanwick in time, your clearance limit is the entry point (assuming you have been cleared as far as that!) and you would be expected to hold there until getting clearance to enter the NAT region. There are no holds mentioned on the charts for this, but you would still be expected to do it. By the sounds of it, some folks here would go bumbling in without a clearance anyway, because they cant or wont follow a few simple rules.
