new post

[Shonick]

on the main page(index) we have a symbol to display which category has new post or not.
But when we access into the category that content new posts and then click back(without view new posts),and then refrest the browser,after that ,the category doesn't show the new post symbol.

How can I do to display the new symbol in this case.I saw in  vBulletin they can do it.Does smf support it?