Class

ComposerChangeListWriterAddressMode.RelativeAddressing

This mode is used for movable content because the slot table will move during composition and absolute addressing will refer to the wrong group (the one where it currently is, not where it is going) so this triggers relative addressing which will use startGroup instead of seek.

Common
RelativeAddressing,

This mode is used for movable content because the slot table will move during composition and absolute addressing will refer to the wrong group (the one where it currently is, not where it is going) so this triggers relative addressing which will use startGroup instead of seek.