You can post a contra entry for any of the types that will do the same as a minus posting.
Some of the posting types do allow a minus posting like a bill.
Example below of a contra Disbursement that is no longer needed and can't be reversed:
Go into Postings and select the Receipt tab.
Select Disbursement Ledger in the drop down.
Put all the information needed for the posting with details it is a cancel/contra item.
Select OK/Next.