Think you're reading that wrong...2nd row is:
[TABLE="class: tgrid, width: 808"]
[TR]
[TH]23.8 mm[/TH]
[TH]15/16"[/TH]
[TH]22.2 mm[/TH]
[TH]7/8"[/TH]
[TD]Obsolete
British size for steel handlebars, common on older
3-speeds.
This size was also used for older British steel
drop bars.[/TD]
[/TR]
[/TABLE]
The first column is stem-clamp diameter. Third column is grip area size.