RMAN: Backup and restore tablespace drop

I am in Oracle 10gR2, I made a full backup in the controlfile that went well (backup database ....), I drop a tablespace (tablespace tbs DRP contents and datafiles) after I have restored The restoration went smoothly without problem (restore database recover database .... then ..) but I do not see the tablespace deleted after the backup.
I do not understand, the backup is OK, but I can not find my tbs?

Thanks in advance.

There are limitations on the restoration of deleted tablespaces:

To restore a tablespace which is deleted you can try to duplicate the basis for a state before the deletion of tablespace with RMAN DUPLICATE and transport the tablespace of the database replicated in the correct basis.

See this link for more help : http://asktom.oracle.com/pls/asktom/...D:515222144417