Question: Where is the Project Reference Number?
The Project Reference number can be found under the Project Details>Overview tab
You can also attach a Project’s Reference number to its tasks using a calculated custom field:
1. Navigate to Setup>Custom Forms>Forms;
2. Create a new Task type custom form;
3. Add a calculated field with the following calculation: Project.Reference Number
4. Save and close the custom form.
Now you can attach this custom form to a task from the Task Details> Custom Forms and the system will automatically pull its project Reference number.
This column is also available to use in Views, Filters and Grouping on Task list
See additional info: Reference Numbers & How They Are Generated