Man pages matching name mh-chart in section 7mh:

mh-chart.7mh.en	debian 10 / mmh
mh-chart.7mh.en	debian 10 / nmh
mh-chart.7mh.en	debian 11 / mmh
mh-chart.7mh.en	debian 11 / nmh
mh-chart.7mh.en	debian 12 / mmh
mh-chart.7mh.en	debian 12 / nmh