When should one use a ‘www’ subdomain?

There are a ton of good reasons to include it, the best of which is here: Yahoo Performance Best Practices Due to the dot rule with cookies, if you don’t have the ‘www.’ then you can’t set two-dot cookies or cross-subdomain cookies a la *.example.com. There are two pertinent impacts. First it means that any … Read more

What are the allowed characters in a subdomain?

Letters (except stressed à), Numbers 0-9 and Hyphen. http://en.wikipedia.org/wiki/Domain_name excerpt: Valid characters that can be used in a domain name are: a-z 0-9 – but not as a starting or ending character . as a separator for the textual portions of a domain name From https://www.rfc-editor.org/rfc/rfc1035 Various objects and parameters in the DNS have size … Read more