Not specifically my field, but the documents below seem convincing (multilingual documentation of a respected auto builder).

-> "7.4 MASSAVERBINDINGEN
Bij elektronische systemen wordt onderscheid gemaakt tussen verschillende massaverbindingen. Er zijn twee verschillende massa's, namelijk een schakelmassa en een meetmassa."
http://www.daf.eu/SiteCollectionDocuments/Bodybuilders_info/...

-> "7.4 EARTH CONNECTIONS
When using electronic systems, a differentiation is made between earth connections. There are two different types of earth, namely power earth
and test or signal earth."
http://www.daf.eu/SiteCollectionDocuments/Bodybuilders_info/...

See also -> "In traditional electrical engineering separate earthing systems were used, for example, signal earth, computer earth, power earth, lightning earth etc. etc."
http://www.copperinfo.co.uk/power-quality/downloads/pqug/61-...