how to stop people from breaking your comment system by writing quotes
255
How can I prevent SQL injection in PHP?
68981
Improve the usability/intuitiveness of direct comment links
108137
Is it OK to leave "What have you tried?" comments?
47581
Marking comments as 'addressed by edit' to reduce noise
44432
Allow anyone to comment but hide low-rep users' comments until reviewed
34339
Lower the amount of reputation needed to comment
44513
disable comments if array exists
56841
Make it more obvious that commenting is only possible after earning certain reputation
73116
How to stop spam in comments
51569
Don't remove the @ part of my comment
38686
Zombie comments (aka wrong comments count when destroying a spammer who posted comments)
153027
Quoting someones comment in own answer
86202
What makes a good/valid +1 comment?
90154
Difficult to lose the "converted to a comment" status message
72668
Dealing with "difficult" usernames in targeted comments
90462
Marking comment as an answer?
63208
Making a Comment on a page without being on that page?