(04 Jun 2015, 8:16 pm)Dan wrote Thanks for clarifying.
I think it was said originally that it was related to an interworking pattern - they didn't gain full branding as service 6 interworks (or again, possibly interworkED) with another service.
Always thought that reasoning was baffling - why bother branding the service at all? If it was that important to brand the service, why not put the branding on both sides for both services?
Of course, cheaper to only pay for vinyls for one side of a bus!
I think it did interwork with the 42 once an hour.