The BrickLink website, which now has apparently been subsumed by LEGO, requires your birth year to enter – you can't enter at all if you input a year.
I don't know you, but I refuse to give this kind of information. So bye bye BrickLink!
I contacted their customer service and told them that I'll simply avoid the BrickLink website if it requires my birth year. Their loss.
If you also disagree with this I encourage you to get in touch with them as well.
1111 is invalid but 1911 works