This document describes the PQ9 and CS14 electrical and mechanical subsystem interface standards for PocketQubes an CubeSats. It is a lean alternative compared to the PC/104 and PQ60 which are widely adopted by the small sat community. The objective is to ensure cross-vendor compatibility and reduced the set of required interfaces. For data communication RS-485 is used and only a few unregulated power distribution busses are provided. The standard comes at the cost of reduced versatility and design freedom for developers, but it will save volume, power, cost and time and reduces the risk for compatibility issues.