The automatic edit summary for "undo" and "revert" actions currently embeds the internal representation of the IPv6 address. Aside being not so human-friendly, it is also inconsistent because in the same context on the same history page, an entry for contributions from an IPv6 address are formatted in a human-friendly way.
. . (Reverted edits by 2605:E000:B4C5:BC00:FD50:8C3:3C70:DEA3 (talk) to last version by Chai-alice) (undo | thank)
(cur | prev) 12:50, 29 September 2016 2605:e000:b4c5:bc00:fd50:8c3:3c70:dea3 (talk) . .
(cur | prev) 12:49, 29 September 2016 2605:e000:b4c5:bc00:fd50:8c3:3c70:dea3 (talk) . .
These two should use the same formatting.