| 摘要 |
A consuming device effects a specific function by using a content of an information package containing a plurality of charged contents while permitting a user to get a refund in response to the amount of actually used contents. A used content ID list of IDs of charged contents having been used so far is stored in nonvolatile memory in such a way as prevents the list from being altered by any person. If a content to be used has never been used until then, the ID of the content is added to used content ID list. The user can get a refund according to the amount of used contents. A navigation system is also disclosed. The navigation system enables the user to lock the use permission, issue a refund request after use permission locking, and unlock the use permission lock.
|
