00/12 is the description. The rest of them are 01, 02, etc...

It all works great if you are actually subscribed to the mailing list. The kernel "lore" site has a better interface to the mailing lists and can download stuff as mbox files - https://lore.kernel.org/all/20220329165900.1139885-1-ascull@...

There is also a service called "patchwork" that collects these patches in a web page format

the git-send-email format for a patch series is the cover letter (the one you are looking at) and then one message per commit (subsequent emails in the thread).

mailman is not the best interface for reading these; people would normally use their mail client, or specialised tools like patchwork.

e.g. this series on patchwork: https://patchwork.ozlabs.org/project/uboot/cover/20220320114...

(click 'expand' in the 'series' line)