This user does not put two spaces after a full stop.
A, B, and A and B
This user prefers to use the serial commaonly when its omission can be confusing.
’s
Thi's user know's that not every word that end's with s need's an apostrophe and will remove misused apostrophe's from Wikipedia with extreme prejudice.
Hello Zepheus! Welcome to Wikipedia! Thank you for your contributions. If you decide that you need help, check out Wikipedia:Where to ask a question, ask me on my talk page, or place {{helpme}} on your talk page and someone will show up shortly to answer your questions. Please remember to sign your name on talk pages using four tildes (~~~~); this will automatically produce your name and the date. Below are some recommended guidelines to facilitate your involvement. Happy Editing! --