Annotation - Chapter 16, Page 176
Arper sitting: Opposition. Shadder mincer: Shadow minister.
A shadow minister does not make government policy but argues against it. SW In England's current parliamentary system, the party that holds a majority in Parliament appoints the Cabinet ministers. The second largest party in Parliament, the opposition, maintains a corresponding Shadow Cabinet whose role is mainly symbolic. For instance, the shadow minister for health is the person who presumably would be in charge of the Department of Health if the opposition party were in power, and offers public criticism of the ruling party's health policy.
The role of the Wes Mincer or shadder mincer seems slightly different: he appears to be second in command to the Pry Mincer, but in this context the role seems to be almost a separate branch of government with separate and secret traditions. The idea of an unbroken line of shadder mincers supports BW's view that the roles of the Big 2 are not only political but mythological, so that the Wes Mincer stands in for the ultimate "opposition": night and death (see Diana and Aunty).