How to create my own SPDX License and identifier

I am a smart contract developer since 2018 and I’d like to have my own SPDX License File and Identifier, since there are some custom projects that should be protected with a specific license since every contract code is public on almost every blockchain.

I’d like to know what are the steps to register my license file with SPDX and get listed on website.

This may help you: license-list-XML/ at master · spdx/license-list-XML · GitHub