After a custom field has been created, its field type cannot be changed.
If a task belongs to multiple projects that have different custom fields, all fields will appear in the right pane’s task details.
You can display up to 3 custom fields in the task list, but up to 60 on an individual task. To change which fields are displayed, go to the Custom Fields Tab within the project settings and click on the gear icon next to each field and change display settings.
Since custom fields are global to your Organization, edits made to them will apply globally to all the projects you use the field with.
If you remove a drop-down item as an option in your field, tasks that use that item will retain the deleted item. The field could then be changed to another value, but you are not able to change a field back to a deleted item.
Reducing your field’s decimal places will retain all current values, but they will be rounded up/down. Increase your field’s decimal places and the original value will appear again.
Removing a field only removes it from the current project, it does not delete the field entirely. Other projects in your Organization with the same field will retain it and the field could still be added to other projects in your Organization.
Adjusting a task’s custom field value will automatically re-sort the project.