For those curious what the legible portion of it says, the runes spell out this (assuming phonetics consistent with the Elder Futhark it appears to be):

>I D I B E R U G

As the article speculated, it might be a name. But we don't know.

From the nice photograph at the top of the article, there is more carving on the stone, but it doesn't tell us a lot:

> I? Z B ? L A E

These letters probably don't spell out anything meaningful, at least in a literal sense. They could be intended for another purpose; they could be initials of names, they could be intended as "magical" (or have some other ritualistic/religious purpose), or they could just be complete gibberish.

I personally think the theory of it being a grave stone, naming the dead seems like the strongest explanation, as that does seem to be a name; though we cannot be certain even of that. The rest of it? We can only speculate.

But what it says on the runestone is not what makes this find most valuable; the age is the significant part. Finding an example of runic writing that far north, that early. We don't know much the development of runic writing; but this helps add to our understanding. IT most likely did develop from a north italic or etruscan script; We find some very old germanic artifacts using such scripts. But we have yet to find anything that might show us a transition from that to Futhark. previously we don't see anything that looks like north germanic runes earlier than 150; which would put this artifact right on that same cusp.