>>24637638
>he [Howland Reed] probably has something to prove that he's Rhaegar's son.

What could he have, a birth certificate or some other document? Why would anybody believe a backwoods hillbilly waving around a piece of paper?

The only way Jon Snow can prove he's Rhaegar and Lyanna's son is being accepted by one of Daenerys' dragons, which is most likely how it'll happen (not that Gurm will ever finish the story).