For tenants of foreclosed landlords, there is a special federal law called the Protecting Tenants at Foreclosure Act of 2009 ["PTFA"], which is similar to the California law requiring 90 days' notice, etc. It is an important part of the process, particularly to use the law and get a fair judge. This is usually done during the motion to quash phase of the lawsuit.
The federal PTFA law supersedes the California law, so that a landlord trying to evict you has to do so under the Federal Law not the California law, where there are any differences. In federal law, it is called Ejectment, and it has no time priority, which the Unlawful Detainer lawsuit has. Federal judges try not to lower themselves to handling eviction cases, and so far have come up with a variety of reasons for refusing to take on the eviction case, but we are still hopeful that one day a federal judge will recognize the tenants' rights and start accepting those cases.
By filing the Notice of Removal, you are literally making a federal case out of the eviction. It requires a filing in the federal courthouse and a copy filed in the eviction case. Filing that Notice of Removal stops the eviction at least until 30 days after the federal judge "Remands" the case back to the eviction court. Just trying to get the case transferred to the federal court can have a total effect of up to months, and luckily staying in the federal court for trial.