When a string identifying a variable is passsed through an RPC call, the server follows a specific rule to interpret the variable name. If the string contains several periods in it, the server first searches for a registered variable of the name only up to the first period. If this is not found, the string up to the second period is searched for and so on. When a match is found, the server looks at the hook attributes for the registered variable. If the hook for the present function (read or write) is found, that function is called to handle the read or write request. If there are no hooks, then a default handler is called.