I can understand the confusion regarding where Rainbow begins & ends. "Rainbow" is a commonly used term to identify a region within the unincorporated area of Fallbrook. Rainbow, the San Diego County area of De Luz, and Fallbrook all have the 92028 zip code. There is the Valecitos School District lines that identitfy the boundaries of the K-8 school in Rainbow. This school district lines do go down Rice Canyon and they include Rainbow Glen and the streets off of it. Those school district lines might be the easiest way to identify Rainbow. As another thought, there is also the Rainbow Planning Group and they might have some type of boundry lines that identify their area of jurisdiction.