Checking missing clips
The Assignment List lets you see if placeholders are complete and ready for air.
You can see thumbnails for placeholders with linked clips, which can also be identified by Ready status in the Assignment List. The thumbnail is blank for placeholders with missing clips.
To display placeholders with missing clips only, click the
Missing Placeholders Only button. 
Only placeholders with missing clips and Not Ready status are displayed.
The Missing Placeholders Only button displays in blue.
If you want to see the entire list of placeholders, click the Missing Placeholders Only button again.