According to the Roman Catholic Baltimore catechism...
A. An Indulgence is the remission in whole or in part of the temporal punishment due to sin.Q. 839. What is an Indulgence?
The RC hopes to get around the uncomfortable, anti-Scriptural position of his church by saying the "remission of sin" is not the same thing as "forgiving a sin."
Are we buying that one? Anyone? Anyone?
Why would the reformed Calvinist do that? Calvinists don't have any teachings on sin or punishment, just a check to see whether or not you're a star-bellied Sneech (predestined to heaven) or one of the Sneeches with no stars upon thars (those poor souls Cauvin's little pocket deity created solely for the purpose of eternal damnation in the lake of fire).
Getting back to the Catholic Church, though, there is no conflict between what I said, what the answer you posted said, and what Scripture says.
Thanks for the help.