• Make the URL human-readable. If that’s not possible, put a simple URL on the page, and redirect to the machine-readable URL
• Keep the URL short.
• Use whole words, where possible.
• String words together without hyphens or underscores. Use dots to separate the company, the department, and the country. For instance: IBM.pc.us.com
• Avoid variations in capitalization. Who can remember SiLiCON VaLLeY capitalization?
• If you use the year, use all four digits.
• Avoid zero, because people will type the letter O.
• Avoid all special characters, because people may not have them on their keyboards.
• If you include the year or date in your URL, write that out in full. For instance, 200210.

Obtain URLs that will enable users to find your site easily. —IBM (1999)

If users can remember your domain name, they can at least get to your home page, from which navigation and search are hopefully sufficient to allow them to find the page they need even if they don’t have the rest of the URL. …Good domain names that are easy to remember and easy to spell are the Internet’s equivalent of a Fifth Avenue real estate location in the physical world.

Our usability studies have shown that users rely on reading URLs when they try to decipher the structure of a site or the possible results of following a hyperlink…. Because we know that users try to understand URLs we have an obligation to make them understandable.—Nielsen (1999f)

See: IBM (1999), Nielsen (1999f)