Okay, not much of a response but, taking our little sample, it would appear 100% of pilots are aware of the 250kt below FL100 limit and are also aware that ATC cannot lift it in open FIR.
Why then, do so many pilots ask? If no procedure speed limits are published, why ask if there are any speed restrictions? The only reasons for asking in my mind would be if speed control had previously been applied in Class A airspace and not removed, which is not the case in most instances, or, the pilot is seeking to remain in excess of 250kt IAS below FL100.
Again, if this is the case, I am not seeking to berate pilots for asking, but rather there appears to be little awareness of the 250kt limit amongst controllers at my unit, resulting in a "No speed restriction" reply in most cases. Before I take actions to remmedy this, I need to be sure that it is the 250kt/FL100 restriction that pilots are refering to when they ask.
Rgds,
Hippy.