There are no rules for ccTLDs, which their countries like to claim as sovereign property (see https://meetings.icann.org/en/dublin54/schedule/wed-ccnso-me... and https://gac.icann.org/principles-and-guidelines/public/princ... for some of the views)

Some ccTLDS voluntarily agree to abide by the same rules and operational requirements as the gTLDs - https://www.icann.org/resources/pages/cctld-2012-02-25-en has more details.

This means, for example, than ccTLDs aren’t bound by the findings from SAC053 at https://www.icann.org/en/system/files/files/sac-053-en.pdf which have been included in the gTLD contracts.