I agree that it is not always clear - the R&N forum notes say ".... Also, items that may be of interest to professional pilots." - so it would easy to post accidents as items of interest if you don't know about the more specific forum.
And some may need some updating. How many understand the term 'Bash' or know anything about one 22 years ago? Quote: "A forum for announcements and anything else to do with the PPRuNe Bashes such as the 20th May 2000 Ash Bash."