It is in the interest of both parties that the other party covenant to comply with all relevant and applicable laws during the term of the lease. Compliance with environmental laws are often included in this section. Depending on the nature of the building, and location, as well as the business of the tenant, this provision will vary in complexity. Parties usually try to limit or apportion their liability to one another for any costs arising out of any environmental cleanups or any violations under applicable environmental legislation. No nuisance - this is usually in relation to the other tenants in the building. This provision usually ties into the right of quiet enjoyment of the leased premises for all the tenants. Rules and Regulations - This is twofold: 1) if the landlord wants warranties that the tenant will comply with applicable laws and regulations to ensure that the tenant will continue to pay amounts due; 2) a landlord may take a security interest in the business of the tenant in case of a breach by the tenant (in this case, it would be in the landlord's best interest to ensure that all applicable business fees and obligations are paid and not in arrears)