The main change here is that now the official mirrors are the official mirrors managed by cluster adm team.
The other mirrors are now named community mirrors.
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Remove all mirrors sections [1] (much outdated information) in favor of a small and unified one [2].
I checked every single mirror (for each protocol) and removed all that is not responding or that has duplicate IPs with another mirror [3].
This was discussed with clusteradm, but the text needs review and possible improvements.
1 - handbook/mirrors-http, handbook/mirrors-ftp, handbook/mirrors-rsync, handbook/eresources-web