What is the 'ancestral term' in the LS coupling scheme?

Question

On the physics.nist.gov site: http://physics.nist.gov/Pubs/AtSpec/node06.html

The table titled "Atomic structural hierarchy in LS coupling and names for the groups of all transitions between structural entities" contains the hierarchy of atomic LS coupling. But there is a rather interesting footnote in the table: The letter $\gamma$ represents any additional quantum numbers, such as ancestral terms, necessary to specify a particular term.

What's ancestral term? Is there an example of this in the literature?

Answer 1

"Ancestral Terms" are terms such as parent and grandparent terms that couple to form the final term.

For example, if you see $3d^7(^4F)4s4p(^3P°) ^6F°_{9/2}$

this means 7 3d electons couple to form a $^4F$ grandparent term

the 4s and 4p electrons couple to form a $^3P°$ parent term and

the grandparent and parent terms couple to form the final $^6F°$ term.

The above is one of several example given at the NIST page Notations for Different Coupling Schemes