I've heard someone say something like:
It's not a scarlet letter, it's not a mark on your forehead you keep for life.
Obviously this was said in terms of permanency of a badge of shame, or redemption.
The Scarlet Letter was a novel by Nathaniel Hawthorne published in 1850. Two of the definitions I found seem to give this novel as the origin of the term:
a scarlet letter “A,” formerly worn by one convicted of adultery.
Random House Kernerman Webster's College Dictionary
a scarlet A worn as a punitive mark of adultery
History and Etymology for scarlet letter
from such a letter in the novel The Scarlet Letter (1850) by Nathaniel Hawthorne
This one however marks the term as being a historical one:
(Historical Terms) (esp among US Puritans) a scarlet letter A formerly worn by a person convicted of adultery
Collins English Dictionary
The novel The Scarlet Letter is set between the years 1642 to 1649 in the predominantly Puritan Massachusetts Bay Colony. The story focuses on a married woman who gives birth to a daughter by another man through a love affair. She is condemned to wear a scarlet letter 'A' as a mark of shame for being an adulteress:
She is required to wear a scarlet "A" on her dress when she is in front of the townspeople to shame her. The letter "A" stands for adulteress, although this is never said explicitly in the novel. Her sentence required her to stand on the scaffold for three hours, exposed to public humiliation, and to wear the scarlet "A" for the rest of her life.
The Scarlet Letter, Wikipedia
I'm wondering if this is historically accurate, whether a woman was forced to wear this mark or something like it to shame her in such cases.
Also, in any case, I take it that the expression derives from the novel from 1850? What I mean is that even if this scarlet letter was a real thing I'm guessing it entered our language through the popularization of the novel.