code: private boolean notAllowedStart(String startTag) {
  		errorState = errorState && startElements.containsKey(startTag)
  				&& forbiddenIdStartElements.containsKey(startTag);
  		return errorState;
  	}
docs: If error with wrong id tag occurs, the errorState flag will be set. In
  this case some start tags have to be ignored.
  
  @param startTag
  @return {@code true} if {@code startTag} is not allowed and will be ignored
  @see #setupForbiddenStartElements()