7.2.2 Reference and Supporting Surfaces
The reference and supporting surfaces of carriages and guideways are designated as follows.
Standard sizes 5, 7, 9, 12 and 15
Logo side
Wider widths 14, 18, 24 and 42
Logo side
Carriage reference and supporting surfaces
Guideway reference and supporting surfaces
The polished reference side of the carriage is opposite the carriage side with the company logo / type designation. Either side of the guideway can be used as a reference side.