Counting Premium Squares Twice
The situation was that the word FEE was on the board. POD was added, with the D of POD turning FEE to FEED.Hi KBH - I've attached a copy of rule 16 in my own (rather old) Scrabble set, because it seems to refer to the same scenario as rule 16 in your Scrabble set. I've underlined the key part of this rule for your question - namely, common letter.
Under the P was a double word square. One player feels the double word applies to POD only, while the other player feels the double word applies to both POD and FEED.
Seems to be rule 16 in the version of the game we are playing.
Only the common letter played in two words gets a premium counted twice. So if it was the D of POD with the double word square under it, then both words would be doubled.
In your example, only POD gets doubled.
I hope this settles the dispute for you. If you think I've misinterpreted your question, or if you'd like to ask a further question about it, please feel free to use the comments link below this answer.
All the best,