The below Design Guides are not specifications. They supply additional information and are intended as an aid for implementing PICMG specifications.
COM Express interfaces and requirements for Carrier boards
Errata Notification COM_CDG_R2_0_ERRATA001 -January, 2014
MicroTCA Standard Process Model Design Guide
MicroTCA Standard Device Model Design Guide
MicroTCA PCI Express Hot Plug Design Guide
MicroTCA Standard Hardware API Design Guide
Physics Design Guide for Clocks, Gates & Triggers in Instrumentation