An standardized way to validate email addresses. It validates on basic faults like not a valid format, but it also checks if the domain can be mailed by checking A and MX records.
An easy no-hassle way to validate a phone number. Pass a phone number as the first parameter and you can set the second parameter to true to allow the phone number to have a country code like +31
Example:
Zipcode
A way to validate, and properly format in return, Dutch zipcodes. Pass a zipcode as paramater and in return you will get false if the zipcode is not correct. Else you will get a zipcode formatted 1111AA