Use this dialog box to control which styles are purged from the current drawing.
Only styles that are unused in the current drawing are listed. Clear a check box to prevent the style from being purged.
You may need to run the Purge command more than once to remove all unused styles from the drawing. Unused parent styles cannot be purged until unused child styles are purged. The first time you run the Purge command, the unused child styles are removed. The next time you run the Purge command, the unused parent styles are removed.