What is the test for obtaining search and seizure of an anonymous tip?

Thus, before officers can lawfully search or seize the subject of an anonymous tip, the tip must be corroborated by other evidence. "Corroboration of an anonymous tip can take several forms. For example, `"[e]ven observations of seemingly innocent activity provide sufficient corroboration if the anonymous tip casts the activity in a suspicious light...."' [Citations.] Similarly, `[w]hile a person cannot be detained for mere presence in a high crime area without more [citations], this setting is a factor that can lend meaning to the person's behavior. [Citations.]' [Citation.] Other forms of corroboration include the verification of detail provided by the informant through the officer's observations. Some information is so detailed as to be self-verifying, and in some cases verification from other sources can be achieved. [Citation.]" (People v. Ramirez (1996) 41 Cal.App.4th 1608, 1616-1617, 49 Cal.Rptr.2d 311.)