A Lisk username is a unique name that you can assign to your LSK address. While the main purpose of a username is to create a Lisk validator address, users may choose to simply have a name for an account as well.

The following are the rules for selecting a Lisk username:

• It must be a unique name (not already registered by another account);
• You can use only lowercase letters. Uppercase letters are not accepted;
• You may use numbers (0-9);
• Special characters may include any of the following: !@$&_.
• It must be between 1-20 characters long.

To register a Lisk username, you must send a Validator Registration transaction. Note that this type of transaction costs a minimum of 10 LSK tokens. The easiest way to do this is through Lisk Desktop.

Once you login to your account on Lisk Desktop, click "Wallet" on the left hand side. Then, click "Register validator" under Balance.

Next a pop-up will appear explaining how registering a validator works and how validators are selected to secure the network. At this point, you can enter your desired username name, then click the "Go to confirmation" button.

A final pop-up will then appear. This pop-up will show a summary of the Validator registration transaction. After confirming its accuracy, you may click the "Register validator" button to submit your transaction to the Lisk network. Once submitted, your username will be tied to your Lisk account.

Every new block round (103 blocks), the top 101 active validators by stake weight and 2 randomly selected standby validators become eligible to mint a new block. The minimum required validator stake weight for this eligibility is 1000 LSK.

For a more in depth look at how stake weight is calculated for the Lisk staking system, and how users can stake through Lisk Desktop, read our blog post on the Lisk Staking Process.

In order to become an active Lisk Validator, a substantial amount of stake weight must be secured. While this may not be a hurdle for large LSK token holders, some will need to attract stakes from the community.