Modes being considered:

index.star?Parent/Page
index.star?Grandparent/Parent/Page
index.star?[...]/Grandparent/Parent/Page
index.star?page=[...]/Grandparent/Parent/Page
index.star?page=title&parent=id <-- conflicts with standard submit mode syntax; need a synonym for 'parent'.

This could be very useful in a PATH_INFO environment.

Suggestion for 'parent' synonym: origin; implies recognition of non-immediate ancestors.