If the coin does have a mintmark it would be under the "DO" in dollar on the back of the coin.
If you refer to the British Five Pound (Crown) coin, they do not have a mintmark. They were all minted at the Royal Mint in Wales.
If the coin has a Mintmark it is on the back of the coin, above the letters DO in dollar.
RPM is a coin collecting slang for "Repunched Mintmark". It refers to when the mintmark on a coin has been struck twice, and you can see remnants of the first mintmark underneath the second mintmark.
Any mintmark will be found on the reverse of the coin under the wreath above the space between the D and O in "DOLLAR". Keep in mind that your coin could have no mintmark, in which case it would be minted in Philadelphia. If your coin has a mintmark, it will ether be a "CC", a "S" or an "O".
If the coin has a Mintmark it is on the back of the coin, above the letters DO in dollar. If no mintmark the coin was minted in Philadelphia.
The mintmark will be on the reverse of the coin under the wreath. The mintmark will either be a D or S or may have no mintmark, in the case of a coin with no mintmark it was minted in Philadelphia.
What kind of coin? What condition is it in? Does it have a mintmark?
If the coin has a CC mintmark it will be on the reverse
If it is a "s" quarter it will always have the S mintmark. You can find this mintmark usually on the back of the coin. The exact location will depend on the type of quarter.
Yes and no. If your coin was minted in Denver it will have a "D" mintmark, however, if your coin was minted in Philadelphia, it will have no mintmark.
Except on the 1964 issues where the mintmark was located on the reverse of the coin under the olive branch that the eagle is clutching. The mintmark is located on the front of the coin, below Kennedy's face and above the the space after the first 2 numbers of the year. Keep in mind that your coin may have no mintmark, in which case it was struck at the Philadelphia Mint.