About column header "All Flagged Revs messages"
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What is the column header "All Flagged Revs messages" for?
It is the name of an aggregate message group.
About number of columns of the table in Translating:Group statistics.
"All Flagged Revs messages" is not sortable.
A line that should be stripped by the script wasn't. gerrit:60270 should fix that when it runs next.