Board Thread:Help!/@comment-15395126-20150914132623/@comment-1432718-20150917141542

Actually, Tardis:Comma and Tardis:Semi-colon both address your questions, and it appears there is no difference between American and British usage in your examples. (If there is, I'm sure someone will let us know.) If you're interested, you can find most of our grammar rules at Category:Typography and punctuation.

Feel free to correct such errors you find. Sometimes editors edit an existing sentence by adding to or subtracting from it, and that causes errors; some editors just don't have a good grasp of punctuation rules.