Fortigate CLI

Good afternoon guys!

I'm using the CLI of a fortigate 81E, I'm trying to delete a Vlan, but it returns the following response:

FORTIGATE (interface) # delete VLAN_230 The entry is used by other 1 entries Command fail. Return code -23

I know that in GUIME this indicates that there are references in other functions such as policies and addresses.
How can I delete these references by the cli