```
@Documented
@Target({FIELD,METHOD,PARAMETER,LOCAL_VARIABLE})
@Retention(CLASS)
@Nonnull(when=UNKNOWN)
@TypeQualifierNickname
public @interface Nullable
```
The annotated element could be null under some circumstances. In general, this means developers will have to read the documentation to determine when a null value is acceptable and whether it is necessary to check for a null value. When this annotation is applied to a method it applies to the method return value.

Annotation Type Nullable