What does H mean after the date on an Australian Penny?

Answer 1

The "H" is the mintmark indicating that the coin was minted at the Heaton Mint in Birmingham.

All 1912 and 1915 Australian Pennies were minted at the Heaton Mint.

Also, the "H" will appear under the lower scroll and above the date rather than after the date.

Some 1912, 1918 and 1919 British Pennies were also minted at the Heaton Mint. These have the "H" to the left of the date.