Futhorc
Cealc is Calc with its branch structure doubled, and that is nearly the whole description. It sits in manuscript rune-rows and effectively nowhere else: no stanza, no etymology of its own, no use in any running text. Page called letters like this antiquarian pseudo-runes, and Cealc is among the cases where the charge sticks. Today, go looking for the duplicate. Somewhere you are maintaining two of something that was only ever one, and the cost is not the room it takes up but the attention of keeping both in step.