1) don’t make them mandatory (Ireland doesn’t have them so you’ll get a comment from me in your post code field which lowers your data quality)

2) don’t apply the formatting of only your country in the validation… US Zipcode formats are different to UK or Canadian or French post codes.

And when it comes to email addresses and website addresses:

1) make sure your validation is checking for ALL TLDs (me@myemail.info is a valid email address format, even if your validation says no)

2) why not include the “http://” as one of the valid things that can be in an email address… you can always strip it out if your database doesn’t like or want it, but don’t make me struggle for 10 minutes figuring out why my website address won’t validate (particularly as you’ve already peeved me by requiring me to use my personal email address because you don’t accept “.info” as a valid TLD.

And when it comes to names:

1) A space in a surname is not necessarily invalid (O Briain or O Brien are valid surnames)
2) There are other characters other than a hyphen that might occur in a name
3) Test your processing for name types that use different character sets or (heaven forbid) the dreaded Apostrophe of Doom which occurs quite frequently in names like… O’Brien, O’Connor (but not O’Bama)

Ultimately, quality begins with design and planning. If you are targeting international audiences, you should take a little time to make sure your data capture makes sense.

Some bogus address to avoid being called or mailed by the Postbank just because I want to know how much I will have to pay for a new mortgage? Many, many times. Of course, a smart question would be how much potential customers they loose by forcing people to fill in their address, but another is how many people just make something up and how incredibly cluttered their mortgage marketing database must be…