By default, the number format on Cloud is the first or the first two letters of the entity you are creating, followed by a hyphen (-) and a number suffixed to this. For example, the first project you create will be numbered P-1.
You can customize the number formats for various entities you create on Cloud. This can help you:
Adapt to your internal naming conventions and numbering sequence for quoting, project management, and invoicing.
Maintain synchrony in the entity numbers between Cloud and its supported integrations.
To change a numbering format, go to "Settings > Custom > Number Formats." Here, you will see the option to change the number format for various entities.
From the available list of entities, select the entity and change the prefix and the starting number.