Here's a list of common comments for Math.SE newbies.
I've posted them on WordPress.com, but I often got typos after updating that page. Without version control, it's hard to find out the cause of such error.
Questions lacking context
Questions not written in MathJax
To avoid excedding the upper limit of 500 characters, I've copied and pasted several comments and combined them into one.
Text images / Scanned pages from books
Displaystyle in question title
One question per post
Fractions in indices and exponents
Notify question writer for a $\LaTeX$ edit
Some commonly misused tags.
My SQL script for searching old comments
You may execute my comment search by user and keyword by clicking the link.