| Value | Meaning | 
|---|---|
| conservative | Takes care not to overwrite settings when either the source or the target is .init. | 
| aggressive | Only considers the init-ness of the source, so as not to overwrite things with empty strings, but otherwise always considers the source to trump the target. | 
| overwriting | Works like aggressive but also always overwrites bools, regardless of falseness. | 
To what extent a source should overwrite a target when melding.