Annotation Interface Signed

@Documented
@Retention(RUNTIME)
@Target({TYPE_USE,TYPE_PARAMETER})
@SubtypeOf(UnknownSignedness.class)
@DefaultQualifierInHierarchy
@DefaultFor(typeKinds={BYTE,INT,LONG,SHORT,FLOAT,DOUBLE},
            types={Byte.class,Integer.class,Long.class,Short.class,Float.class,Double.class},
            value=EXCEPTION_PARAMETER)
@UpperBoundFor(typeKinds={FLOAT,DOUBLE},
               types={Float.class,Double.class})
public @interface Signed

The value is to be interpreted as signed. That is, if the most significant bit in the bitwise representation is set, then the bits should be interpreted as a negative number.

See the Checker Framework Manual:

Signedness Checker