Walthamstow parking sign (MT & MW meaning)

hellomoto23

I saw a parking sign in Walthamstow, but don't know what it means. I can't post images so I will explain instead: Next to the permit holders only information it also has the initials "MT". Underneath, the information for other people parking also says "MW". I couldn't find any information on the MT and MW initiials on the internet, or on the Waltham Forest council site, but maybe I looked in the wrong place. Does anyone know what they mean?

building_with_lego

Seems to be something to do with zones: https://walthamforest.gov.uk/sites/default/files/CPZ%20list_0.pdf

Map showing the zones: https://walthamforest.gov.uk/sites/default/files/V6%20october%202016%20reduced.pdf