1. Go to the Configuration tab (the cog icon) > Data > Custom fields > Project custom fields, and click the Add button.
2. Type in a name for this field, and select its type.
3. Specify values for Multiple selection and Dropdown custom fields. Select Active to enable your custom field, and decide if you want it to be obligatory.
4. Your custom field is now added to the list and is active.
5. Next time you create a project a new section is available and you can use your defined project custom fields.