From Law wiki, the wiki for law research

An equitable lease is created when one person contracts with another to assign or create a lease, in circumstances where the lease should be created by deed or registered. For most purposes the lessee will be treated in litigation as if the formalities had been observed, under the equitable doctrine of 'equity sees as done that which ought to be done'. However, if the lessee wished to assign the lease to another (see: Assignmentland and property), the presence of covenants (see: Covenant) does not bind the assignee in the same was as for a legal lease.