ZIP+4 has been in place for over THIRTY YEARS.

ZIP+4 code, introduced in 1983, includes the five digits of the ZIP code, a hyphen, and four more digits that determine a more specific location within a given ZIP code.

So WHY don’t coders implement web-forms to accommodate this thirty-year-old standard? 

Seriously.

The developer of the webpage from which the screenshot above was taken (Diamond Mind) even specified TEN DIGITS for the zip code form field!

<input value="" name="postal_code" maxlength="10" class="dm-fb-zip-code" id="dm-fb-zip-code" type="TEXT">

Why go to the trouble of writing a validation script for a zip code field without going to the trouble of limiting the number of input characters? 

More troubling, why specify 10-character maxlength for a five-digit validated field? 

And check this out, the developer specified a maxlength, but didn’t bother to specify “digits only”:

Good Grief Charlie Brown.