Canada 10 cent km 67 or 67a

With reference to the coin in question, I have some with the edge as Philadelphia Reeding and others as Ottawa Reeding. Why is this variant not mentioned?

US Mint in Philadelphia didn't make either of those coins.

I had a look in my Charlton standard catalogue (2021 edition). About half of the 1968 nickel 10-cent pieces were minted at the Philadelphia Mint, due to pressure of other work at the Royal Canadian Mint. The only difference between the two issues is in the number and shape of the grooves in the reeding: the Philadelphia coins have square bottoms, while the Ottawa coins have V-shaped bottoms.

However, no such difference in reeding is mentioned for the 1967 10-cent issues (either .800 or .500 silver), or for the 1968 .500 silver issue.

The US Mint at Philadelphia did not make the coins the OP was asking about so there is no such thing as a “Philadelphia edge” on a 1967 Canadian 10 cent coin.  The Philadelphia Mint made a total of 85,170,000 10 cent coins dated 1968 as detailed in the Mint Report. That is this coin: N#9201 .

Do you understand now?