I moderate comments on my blog.
I use wordpress’s spam filter to routinely sideline comments which appear to be inappropriate. Occasionally a valid comment gets automatically kicked aside by WordPress, and so now and again – very infrequently – I take a look in the trash bucket to see whether this has in fact happened – and retrieve the comment if so.
I prohibit and assign as spam, comments which are, in my view, potentially defamatory to individuals or to organisations. I likewise prohibit offensive or inappropriate language.
Other than that: delighted to get any comments !