Automatically check "Allow comments" for custom post type
109777
Can't add default comments to custom post type
87776
Allow voting on comments from Review interface
76353
How to auto send email when publishing a custom post type?
40702
Add data.SE style "magic links" to comments
93826
How can I include custom post types on a tag page?
117715
Always allow commenting on posts I have previously commented, irrespective of current rep
23614
A method for the OP to accept comments?
146983
Where to put comments in an if-then-else construct?
155996
Auto-upvote comment during Low Quality review when selecting same reason
29011
Block comments in html.erb templates in rails
83927
Are comments safely hidden once the document is compiled?
114102
How to make HTML code inactive with comments
105317
How can I search for specific comments?
92018
Comment Inheritance for C# (actually any language)
128353
How to flag comments as spam?
105916
Auto-expand @username in comments to keep the username up-to-date
7147
Allow for setting comments to "auto-expire", to become "temporary comments"