TL;DR: While we use the same standards as the rest of the network, there are two main differences in how we implement them:
- We are extremely strict on comments. If your comment doesn't fall under the "You should submit a comment if you want to:" header, it will be removed.
- Thanks to our bot and user base, we moderate comments fast.
Are there secret rules hidden somewhere?
Nope! There are no secret rules here. We abide by the pre-made comment page that's on every site of the network, which reads:
Comments are temporary "Post-It" notes left on a question or answer. [...]
You should submit a comment if you want to:
- Request clarification from the author;
- Leave constructive criticism that guides the author in improving the post;
- Add relevant but minor or transient information to a post (e.g. a link to a related question, or an alert to the author that the question has been updated).
Comments are not recommended for any of the following:
- Suggesting corrections that don't fundamentally change the meaning of the post; instead, make or suggest an edit;
- Answering a question or providing an alternate solution to an existing answer; instead, post an actual answer (or edit to expand an existing one);
- Compliments which do not add new information ("+1, great answer!"); instead, upvote it and pay it forward;
- Criticisms which do not add anything constructive ("-1, see previous comments you scallywag!"); instead, downvote (and provide or upvote a better answer if appropriate);
- Secondary discussion or debating a controversial point; please use chat instead;
- Discussion of community behavior or site policies; please use meta instead.
All of this seems pretty standard, and we do adhere to it. If there's a comment leaving clear constructive criticism or suggestions, we leave it. The same goes for clarifying questions. So...
Why does it sound like things are so different here?
We moderate comments to spec, but we might do it a little more...diligently than you're used to on other sites. You might notice that there are many types of comments that fall into neither the "You should submit" nor the "Comments are not recommended for" header above. While most sites will leave them or slowly remove them as they no longer become relevant, on IPS, if your comment doesn't fall under the first header, it will be deleted.
...but not without good reason! The nature of our questions and answers is extremely personal and sensitive.
Over on StackOverflow, there's a meta post every day or two about someone who feels they're being mocked or slighted in the comments (just to pull a few I could find that weren't deleted: 1, 2). These are just the cases where OP feels strongly enough (and is familiar enough with the SE model) to post on meta. And this is just people talking about code.
Now imagine how many times more inflamatory the conversation gets when people are talking about your personal beliefs. Or health issues that you don't even feel comfortable talking to your family about. Things start to get out of control. Fast.1
We developed the IPS Comment Bot to enable us to quickly respond to these kinds of comments. This friendly bot helps us keep track of potentially off-topic or no-longer-needed comments as they're posted so we can quickly remove them. We also post a dump of every comment posted to IPS in our Closet. Together, these two are a big part of how we're able to promptly address new comments.
So, do we moderate comments differently from the rest of the Network?
Well, yes and no. Faster and a little more strictly maybe, for the safety and sanity of our users. But at the core, we hold comments to the same standards the rest of the Network does. There are no "secret rules" here.
In fact, I think the mod comment you referenced sums it up best:
Please note that IPS is fairly strict about using comments as intended. Comments are only for clarifying and improving the question. Partial answers or general thoughts about the situation may be deleted without notice.
Friend is very nitpicky about side comments I don't intend to be taken too seriously
1. There is a looooong history behind this stance on comments. Suffice to say that we became tired of constantly seeing 40/50/60 comments on posts--many of which were of no (or minimal) benefit to anyone at best and extremely detrimental at worst. If you are truly curious and a scroll through our old meta posts doesn't satisfy you, I'd encourage asking a new meta question to get the history all in one place.