We signify things like this via icons in the top right - eg, news, blog posts, questions, books, etc all have different icons 
We use colour to reflect type, eg Frontend dev is red, backend is blue, desktop platforms are purple etc
A combination is used too, so a blue top right colour with a book icon means the thread is about a backend dev book 
Re the three Rails news items, we have three as a fallback - in case our system is down and we need to catch up (so any important news isn’t missed). However if no news item for that portal has ever been posted before then it should only post the latest news item - so not sure why three got posted - I will have to look into it 
Thanks for the comments about PragProg errata, I love seeing it here too 
Edit: just noticed you meant the forum and not the front page. Ideally we’d have thread icons on the forum too, unfortunately this is not possible with discourse atm. So we are currently making do with section name (eg news/chat/questions etc) and colour (eg blue for backend, red for Frontend, etc) :). Hopefully discourse will add thread icons at some point 