Definition
HTML Standard defines ValidityStateFlags
dictionary ValidityStateFlags {
boolean valueMissing = false;
boolean typeMismatch = false;
boolean patternMismatch = false;
boolean tooLong = false;
boolean tooShort = false;
boolean rangeUnderflow = false;
boolean rangeOverflow = false;
boolean stepMismatch = false;
boolean badInput = false;
boolean customError = false;
};