https://en.wikipedia.org/wiki/List_of_postal_codes_in_Austria

This matches EU IBAN codes considering spaces here and there

Find all twitter bootstrap buttons with class "btn".

Find all inputs and buttons with class btn.

Any domain written www.domain.co.uk

Works for all types of comments and even multiline comments in java.

Date javascript

Validate multiple Email-addresses separated by semicolon. No check on allowed domains, just a plain and simple check on the correct structure

Will allow #hash,#tag but not #hash,.

Date Regex for Javascript

Javascript date regex