Reference Geometry :

General term for a sketch-element that is a copy of a sketch-element from a different Mechanism-Editor to the active Mechanism-Editor.

Source Sketch-Element :

A sketch-element, in a moving or stationary Part in a different Mechanism-Editor.

Reference Sketch-Element :

A copy of the Source sketch-element, and its motion, to a Part in the active Mechanism-Editor.

Preparation example:

Two(2) Mechanism-Editors

•Source

•Reference - this is the active editor

A Circle in Source sketch-element

The Circle is in the Source Mechanism-Editor.

To see the Source Mechanism-Editor when the Reference Mechanism-Editor is active.

•Visibility toolbar > Show other Kinematic and Sketch elements

AND

•Right-click Mechanism name-tab of the Source mechanism-Editor and select Show with 'other Kinematic and Sketch elements'.

AND

•View toolbar > Spin or use your arrow keys on your keyboard to spin the model to see the two editors.

STEP 1:Start the Add Reference-Geometry command

The Command-Manager indicates you must select two(2) elements

STEP 2:Select the two elements in the graphics-area

STEP 3:Complete the Command

Result :