The Standards document you are looking for is Standards Document 3 for the Commercial:
http://www.caa.co.uk/docs/33/SRG_FCL_03_A.PDF
and Standards Document 1 for the Instrument initial test
http://www.caa.co.uk/docs/33/SRG_FCL_01.PDF
This document
SHOULD be given to all students as it is for their reference and if your instructor doesn't know what this document is - you should be
very worried.
To answer the questions regarding the commerical (Version 7 is valid as listed on the CAA website)
As determined by the Flight Examiner - any relevant items of the class/type rating skill test to include, if applicable:
i. Aeroplane systems including handling of autopilot
During the diversion leg the applicant may supplement visual navigation techniques with the use of VDF, VOR, NDB, DME and/or GPS information. Only GPS raw data (latitude and longitude or range and bearing from a waypoint) may be used. GPS map displays or “GOTO” facilities will not be permitted. The examiner will deny the use of any aid that would allow the applicant to track directly to the diversion destination. If navigation aids are used, the applicant will be assessed on their correct use.
To answer the questions regarding the Instrument (Version 6 from 2004 is the version listed as valid on the CAA website)
Autopilot and flight director systems may not be used during the test. However, if the aircraft is fitted with this equipment, the applicant may choose to carry out the necessary pre-flight checks to establish the serviceability of the system, it must then be disengaged. The electric trim system however may be used as prescribed by the aircraft flight manual and must be tested. Altitude alerting systems and speed bugs are permitted.
Remember, all documents in the UK are guidance only, and the source document should always be referred to - but these docs were current according to the CAA on posting.