Final answer:
Direct referral from a physician is not a requirement of the Standards of Practice regarding high-grade joint mobilization techniques.
Step-by-step explanation:
Regarding high-grade joint mobilization techniques, the requirement that is not part of the Standards of Practice is D. Direct referral from a physician. While obtaining informed consent, conducting a thorough assessment, and documenting treatment are all essential elements of the Standards of Practice, direct referral from a physician is not specifically mentioned as a requirement.