The sentences that use a comma in a way that is considered contested usage are:
-
Faith, Millie's best friend from summer camp, is coming to visit in a few weeks.
- The use of commas around the appositive can vary depending on style guides.
-
We are passing through New Orleans, Louisiana right before we stop in Houston, Texas.
- The comma before the state name can also be seen as contested since some style guides recommend omitting it if the city and state are used in a sentence without another comma separating them.
In both these cases, the placement and use of commas can vary by style guide or personal preference.