If you only post a link without any comment or explanation, then spam busters will mark your post as a link spam. Next time, try to provide more substantial value, not just a link or a short comment.
I didn't post any link, the user I commended posted the quite helpful link.
And where is it stated that one must make a long, drawn out comment?
Or do you just make up rules?
In Newbies thread, there are Rules read it, Posts like "Thank you", "Joined" etc are not allowed