The use of [sic]

"Indicating the use of nonstandard grammar or spelling.
In rare situations, one may quote from a text that has nonstandard grammar, spelling, or word choice. In such cases, one may want to insert [sic], which means "thus" or "so" in Latin. Using [sic] alerts your reader to the fact that this nonstandard language is not the result of a typo on your part. Always italicize "sic" and enclose it in brackets. There is no need to put a period at the end. Here's an example of when you might use [sic]:
Twelve-year-old Betsy Smith wrote in her diary, "Father is afraid that he will be guilty of beach [sic] of contract."
Here [sic] indicates that the original author wrote "beach of contract," not breach of contract, which is the accepted terminology."
From The Writing Center of the University of North Carolina at Chapel Hill

and further:
"Sic in square brackets is an editing term used with quotations or excerpts. It means 'that’s really how it appears in the original.'

It is used to point out a grammatical error, misspelling, misstatement of fact, or, as above, the unconventional spelling of a name.

For example, you might want to quote the printed introduction to a college catalog:

Maple Leaf College is well-known for it’s [sic] high academic standards.

Sic is the Latin word for 'thus' or 'such.'"
From Daily Writing Tips

Comments made included "said in context." Now I must check how to use sic in transcribing my uncle's letters.