Your second and third "sins" are the ones I most frequently observe - they seem to be present in almost all "Show HN" posts - oh and not providing a link to the

Your second and third "sins" are the ones I most frequently observe - they seem to be present in almost all "Show HN" posts - oh and not providing a link to the web site. A well researched "sins" list in this area might make a great addition to the "Guidelines page" - but there again a poor post is probably an effective indicator for the quality of what is to be found.