OK thanks, Unfortunately I explained this to my FO on the day and ( as is always the case with the challenge everything brigade ) he comes back with " where is that written". I don't really mind that (as it also serves to protect against a huge amount of cross cockpit hot air)...but it would be great to be able to point this out as a reference if someone was willing and able to dig it out. Would like to take you up on the offer of a visit...any contact details? Thanks again.
RMC,
The below is a direct quote from the MATS Pt1, it's freely available online, and contains the rule quotes you need:
Chapter 4
7. Amendments to Clearances
7.1 When an amendment is made to a clearance the new clearance shall be read in full to the pilot and shall automatically cancel any previous clearance. Controllers must be aware, therefore, that if the original clearance included a restriction, e.g. “cross ABC FL150 or below” then the issue of a revised clearance automatically cancels the earlier restriction, unless it is reiterated with the revised clearance.
7.2 Similar care must be exercised when a controller issues a clearance, which amends the vertical profile of an aircraft on an SID. For example, “climb FL120” automatically cancels the vertical profile of the SID. If the profile contains a restriction that provides vertical separation from conflicting traffic on another SID, the restriction must be reiterated, e.g. “climb FL120 cross XYZ 5000 feet or above”, unless separation is ensured by other means.
7.3 Similarly, when controllers issue instructions which amend the SID route, they are to confirm the level profile to be followed, e.g. “fly heading 095, climb FL80” or “route direct EFG, stop climb at altitude 5000 feet”.
Regards
30W