A value specified as carrying a type qualifier annotation is compared with a value that doesn't ever carry that qualifier.
More precisely, a value annotated with a type qualifier specifying when=ALWAYS is compared with a value that where the same type qualifier specifies when=NEVER.
For example, say that @NonNegative is a nickname for the type qualifier annotation @Negative(when=When.NEVER). The following code will generate this warning because the return statement requires a @NonNegative value, but receives one that is marked as @Negative.
public boolean example(@Negative Integer value1, @NonNegative Integer value2) { return value1.equals(value2); }