- copy: A copy of the source item may be made at the new location.
- move: An item may be moved to a new location.
- link: A link may be established to the source at the new location.
- copyLink: A copy or link operation is permitted.
- copyMove: A copy or move operation is permitted.
- linkMove: A link or move operation is permitted.
- all: All operations are permitted.
- none: the item may not be dropped.
- uninitialized: the default value when the effect has not been set, equivalent to all.