Gratuity of 18% was added to my food bill yesterday. Is this the accepted procedure? I'm not averse to tipping, in fact I would have given 20%. Only two of us.

Depends on the group size, less then 5, shouldn't be any

Not the norm for any restaurant with Less than 6 people...

Yes depends on group size typically...

Firstly I'd like to say welcome to Portland, ME! Honestly, I've been a regular there for so long that I don't even look at the bill anymore. I have seen a lot of places in this area add gratuity to their check depending on the number of persons in a party, or dependant on the overall visit cost. Even our Denny's does that.