You know the person well, or did, long ago. So it wouldn't be enough to just shake hands or nod when you say hello. But a hug...?
Hugs are good for sharing warmth and humanity, but we get in situations where we're just not sure a hug is appropriate. It's a rich vein of thought that Emily Flake explores in the slender book That Was Awkward: The Art and Etiquette of the Awkward Hug.
Side hugs? Leaning-over hugs? Short, barely-touching hugs? There are so many variations, and so many questions. Emily Flake visits to answer a few.