It’s a number of the official documents you get from IRCC. It has either:
four numbers, a hyphen and four more numbers (Example: 0000-0000) for PR or
two numbers, a hyphen, four numbers, a hyphen and four more numbers (Example: 00-0000-0000) for temporary permits
As a settlement organization funded by IRCC Skeena Diversity is obligated to collect UCI number of each client to be able to provide services for free. This information is kept secured and confidential.