The Costa-Hawkins Rental Housing Act is a 1995 California state law that allows landlords who rent single-family houses to raise rents as much as they like - it exempts them from rent control laws that end up only applying to apartments. This is particularly relevant in places like Oakland where we have many houses and many people who rent houses. It severely weakens house renters' positions in relation to their landlords, and is one of the contributing factors to gentrification.
The law also says that buildings built after Feb. 1, 1995 are not subject to rent control (that's from the 2008 president's report of the San Francisco Apartment Association - an association of apartment property owners. The report is called "Give Thanks for Costa-Hawkins"!!!)