An alphanumeric username is a username that includes both letters and numbers. It can be a combination of uppercase and lowercase letters, as well as special characters. Here are a few examples of alphanumeric usernames:

1. John01: This username combines the name "John" with the number "01" [1].
2. JOhnSm1th: This username includes a mix of uppercase and lowercase letters, as well as the number "1" [1].
3. Gr@y&At0m: This username incorporates uppercase and lowercase letters, as well as special characters like "@" and "&" [2].
4. (r@yz&at0My: This username also includes a mix of letters and special characters [2].
5. Gr8yz&atOMY!: This username combines letters, numbers, and special characters [2].

Remember that alphanumeric usernames can vary depending on the specific requirements set by the platform or website you are using. Some platforms may have additional restrictions or guidelines for creating usernames.

Learn more:

1. What Are Alphanumeric Characters? How Are They Useful in ...
2. Alphanumeric Characters and Alphanumeric Password Requirements | Okta
3. How create username with alpha numeric characters - Software Support - PKP Community Forum