In commercial property much of the law, especially as to disputes and basic responsibilities, is based on freedom of contract of the common law including the implied terms of precedent decisions of wide-ranging case law such as the meaning of "good and substantial repair". Implied principles include "non-derogation from grant" and "quiet enjoyment". All businesses which are tenants (lessees) must decide whether to contract in or outside of Part II of the Landlord and Tenant Act 1954 which gives them "business security of tenure". If not, it generally applies by default. This "security of tenure" is expressly subject to common reasons and associated mechanisms for a landlord to obtain back the premises. If a landlord is selling a block and a qualifying tenant occupies more than 50%, the tenant should be given the right of first refusal at the asking price to buy the block. As in most jurisdictions the law on rigorous adherence to lease terms on unlawful subletting and assignment can be strictly enforced, resulting in financial and premises loss if broken. Failure to repay a rent demand, unlike residential, can result in direct landlord's repossession ("peaceable re-entry") through a commercial landlord's right to the use of "self-help" evictions. The taking of a tenant's goods without a court-issued warrant (flowing from a court order or outstanding tax demand) (distress) has been banned.