You talking about the one seen in the "topics listing"?
I think to each person the "new" sign will be seen at different times, and will go away once you have viewed a topic.
Too test this theory, clear your browsers cache and then revisit a topic that you just looked at, and the "new" sign should appear again.
Or refresh your browser every so often, that will give you a good idea as to when there has been a new post since the last time you viewed it.

Otherwise to answer your question, no you don't insert it it appears on its own, and will only appear as "new" to someone who has yet to view it.
At least this is the best I know how to explain it

Quote:


So sort of what I said but a lot less words and making more sense?