Lore: ancestor and descendant (lore)

When significantly generationally distant relatives (at least beyond grandparent or grandchild) are present in the post. This is probably made possible due things such as time travel, an immortal or long-lived ancestor, resurrection, excessive inbreeding, or simply a cameo appearance of them (such as in a photograph or painting).

Another usage for this is if the familial relation between parties involved is ambiguous other than the fact that one is the ancestor of the other party and other one is the descendant of the ancestor.