Valid options

DROP	drops a specific index (index name parameter must be used)
DROP ALL	drops all indexes associated with a table
PRE DROP	drops any indexes associated with a table that has the pre-drop flag set or that is ready for a rebuild
BUILD	builds a specific index if an index name is passed. Otherwise builds all indexes that were pre-dropped
BUILD ALL	builds all indexes

Note: Under normal scheduler processing, a PRE DROP is performed before a table update followed by a BUILD after the update.