How to interpret the rank of features?

Is the rank of feature in CTF means the importance of features, just like rank in PCA?
In 2.2.0-compare-feature-ranks/1.0.0-rankings.ipynb, what is the reason of claiming 'pos in both is more vaginal and more neg is C-section'?
Thank you for your help!

Start with 2.2.0-compare-feature-ranks/1.0.0-rankings.ipynb and inspect how feature ranks and the CTF results are presented. Clarify what the rank represents and document the reasoning behind the statement about positive and negative ranks; the notebook should make both interpretations understandable.

Written by the indexing model from the issue text.