Ior is the dipthon “io”
Anglo-Saxon Rune Poem (from ragweedforge.com)
Ior is a river fish and yet it always feeds on land;
it has a fair abode encompassed by water, where it lives in happiness
Ior is the rune for October, which I find to be fitting and appropriate. In most of modern European lore (starting from the fall of Rome forward) the time following the autumnal equinox until the first part of spring, was a time when the spirits of the dead became more active. Some see it as the veil between worlds opening. In other views, it has to do with the increased darkness, allow the revenants who lay in their barrows to move about longer and more freely, then the brighter months of spring and summer.
As Ior represents being in the liminal point, standing in the boundary between things, it is a key sign for being in the boundary between life and death, and thus being able to communicate or interact with both, and yet be tied to neither. The role often required by many people from many cultures, was one who could communicate between the living and the dead, and to help the relationship between them. Sometimes it would happen in families. Other times, a trained specialist would be required who can help navigate the challenges that the living faced, especially during the darker days.