What is the test for reasonable suspicion for detention of an anonymous tip-off?

^2. In reaching this conclusion, we find it unnecessary to rely on People v. Dolly (2007) 40 Cal.4th 458, which the People cite to argue that public safety justified the detention. We note that Dolly is distinguishable in important respects. In Dolly, an anonymous tipster-victim supplied reasonable suspicion for a detention by providing an accurate description of a suspect with a cast on his arm who committed a violent crime and still had the potential to do so, telling police specifically where the suspect was parked, and describing the make and color of the car the suspect was in. (40 Cal.4th at pp. 462, 465-470.) Among other things, here there was no similar specific description of the suspects' vehicle parked in a specific location.