It can be useful to set a custom status for a job, for example so you can look at your jobs list and see whether the job is waiting on an external service or a client to complete a task.
A custom status will display in the 'status' column on job lists, next to the pending/ready/blocked status.
Create custom statuses
Click on Settings > Lookups > Task status > Add item
When you are done, remember to click 'Save'.
Add a custom status to a task
Go to Settings > Jobs > Select a job or add new > Tasks > Add task
Click the 'Advanced' tab and select the status: