Can "new posts" be saved with logged-in account

If I'm logged in on my pc and read a post, then I go look at the same post on my phone, posts I already saw on my pc but not yet on my phone are flagged as new (and vice versa). Could my account just remember what I've read instead of local cookies? On an active thread, it makes it difficult to know which posts are actually new, if any, so I have to rescan all of them.