A formal invitation

If an invitation (say, to a wedding) says "Dress: Formal", what does that mean exactly? Dinner suit?

And anyone got any experience with a really great boarding kennel? We're kind of wavering towards this one...

Welcome to -- Harkleah Meadows Ltd -- Boarding kennels with a difference

Pretty much because of all the pictures of happy dogs on the website. We're suckers for pictures of happy dogs... And the dog runs look more spacious than others we've seen...