Answer: Not all customers created within a company's Customer Records are necessarily visited by all route salespeople, or visited at all for that matter. Prime examples of this are Head Office or MultiVendor Customer Records that are not only not visited but are often in entirely different states or even countries than that which is serviced. It can also be said that it's not always desirable for every single Customer Record to be available on every handheld computer, as this will only increase the number of customers a route salesperson needs to scroll through to find the one that they're servicing.
The solution to this problem is to use Customer Route Groups to control what Customer Records are available on which handheld computers. Using Customer Route Groups allows customers to be available on only specific handheld computers and allows them to be unavailable on all handheld computers by simply not assigning their Customer Route Group to any Mobile Unit Record. For information on creating and using Customer Route Groups, please read Solid Know How Article #86 What are Customer Route Groups (CRG) and how to Use, Create, and Assign Them?