Los Angeles County’s rent control ordinance requires a landlord to submit a copy of a three-day notice to pay rent or quit to the LA County Dept. of Consumer & Business Affairs.  This decision holds that while the notice requirement is mandatory, the ordinance does not make compliance with that requirement either a condition precedent to eviction that the landlord must prove as part of its unlawful detainer burden of proof, nor is non-compliance with the notice requirement an affirmative defense that the tenant can raise as a defense to an unlawful detainer action.