Actually the guidebook does mention it, but I presumed people check that. My fault. I always check the bill before paying and check if a a tip/service charge has already been added, which happens in several European countries and some restaurants in the USA. When someone visits the USA does one say expect to tip 15-20% at a restaurant unless it is already included or expect to tip 15-20% at a restaurant?

Technically wiki is not wrong. It just doesn't mention that sometimes it is included for you so you don't have a choice. I'm wrong for not writing the entire 2 paragraphs in Lonely Planet and putting just the sentence about expecting 10% tip/service charge.

I have much faith in the Lonely Planet Guide Book. It is written by people who live at the location. But, I don't take it as gospel. I look at other sources as well. I have visited Austria several times and have Austrian friends as well. I also pay attention and see what people do. And as you can see with the added links by uk1, there are now 4-5 sources that state a 10% tip and I haven't seen one source that says otherwise.