reference edge; guide edge
Technical term in computing and engineering for a physical or logical edge used as a reference for alignment, measurement, or positioning.
Place the components along the reference edge of the board.
In this CAD software, you can specify the distance from the guide edge.
Compound of 基準 (standard, reference) and 縁 (edge, rim). The exact historical derivation is uncertain; the term is a modern technical coinage.