10 Cent Coins 1953 To 1967 Die Axis ?

According to the 74th edition of Charlton:
The die axis of a 1964 10 cent coin is coinage.
I assume that, as it is shown together with the 1953 coins to Date.
In these specs, it shows 2 times the symbols for coinage.
In a previous Charlton edition, it depicts both symbols, coinage and medal.
does anyone know why that is? ? and which one is correct?
does it have a special meaning? or is it a simple printing error?
Going on the same assumption, I take it that this applies to all the coins listed right below the 1953 dimes, right down to the 1967 dimes.
If so, how do we know which is correct for which year?
I have a 1964 10 cent coin which is 100% medal axis. unfortunately, I have no other 1964 suitable to compare, as my other 1964 has a huge die rotation.
Can anyone shine some light on this, please?
Thank you everyone for your help.
H