Going through other Apple applications on macOS, X-Apple-I-MD and X-Apple-I-MD-M appeared in other communications as well, iTunes, GitHub Pages documentation
X-APPLE-I-MD-M.
This header is part of a suite of "identity" headers often seen together, including: x-apple-i-md-m
: The value is a long, encrypted string containing hardware-specific metadata and epoch-based timestamps. 🛡 Role in "Grand Slam" Authentication x-apple-i-md-m