Consider the following sentence:
Huego becomes fuego by discarding its "h" in favor of "f".
Do not omit the trailing "s", which is key to the overall meaning here.
Nueve comes from the Latin word "nueve", which also gives us the English word, nine.
I know American English mandates punctuation marks going within the quotes. I want to know how it treats contexts where the quotes contain a single letter or word such as the above examples? I am only talking about formal American English style guidelines.
P.S. I know I can get rid of the quotes by using italics or some other technique to delimit the quoted text here. But I don't want to do that. I am just curious to know how AP (Associated Press Manual of Style) or CMS (Chicago Manual of Style) would treat punctuation in this context.