The Definition tab displays the member assembly connection properties as they are defined in the reference data. The property name appears on the left side of the grid and the corresponding property value appears on the right side of the grid. If you selected more than one assembly connection and then selected the properties command, only the common properties between the selected assembly connections display.
The properties that display depend on what you defined in the reference data. Refer to the Structure Reference Data Guide for more information on the properties.