Force options are used to override the default behavior of dpkg. These options should be used with some forethought, due to the potentially dangerous nature of these commands. Each of these commands forces dpkg to perform in a way that is foreign to its normal behavior. This opens possibilities for damage to the system that are otherwise well contained.
The force options have two actions:
--force-<thing> which reduces errors on <thing> to warnings
--refuse-<thing> stops execution on encountering errors on <thing>
--no-force-<thing> == --refuse-<thing>
thus each of the options in this section can be preceded by either of the above prefixes.