Question
How to delete all the iterations of drawing format that are not released?

Hi there, the above is the screenshot about the issue: the released version of the drawing format is B released in 12 months ago. Since then, the drawing format has been accidentally revised to Rev H. We need to delete the drawing formats of revision C, D, E, F, G, and H. however, Windchill doesn't allow it, saying they are used in other workspaces.
How to delete them and only keep the released version B?
Thanks.
JS

