Nikki has an equitable lease and this should be protected by the registration of a Land Charge. The lease operates in equity only because the relevant formalities for the proper execution of a deed have not been complied with. Under the Law of Property (Miscellaneous Provisions) Act 1989, a deed must be signed, witnessed, and delivered to be effective. In this case, the failure to meet these requirements means the lease cannot be a legal lease and operates instead as an equitable lease. This should be protected by way of a notice against the landlord's title if it is registered or by registering a Class C(iv) Land Charge if the landlord's title is unregistered. 

Key Point: A lease must meet specific formalities to be legally enforceable, and failure to comply with these results in the lease being equitable, requiring protection through appropriate registration.