Archiving Manager Database

Does anybody know the process to Purge/Archive Manager Server DB? The webMethods_Database_Guide_6.5_and_6.5.1.pdf guide has procedure only to archive Analysis,process archive and process tracker DBs.

In particular, seems like blob data in WMS_NOTIF_DETAIL table in Manager Server DB taking 80% of the total space. Any idea what this table is used for? How to purge it ?