anchor.diff:  
   [[Account]]Account:: A record that contains details about the customer such as name, address, email address, phone number, etc. Also referred to as a "customer account."
   
  -API:: The software intermediary that enables communication between two applications. For more information, see the https://killbill.github.io/slate/[_Kill Bill API Reference_].
  -
   == B
   
  -Billing Period:: The period for which the customer is billed. _Examples:_ `MONTHLY`, `ANNUAL`
  +Billing Period:: The frequency in which Kill Bill invoices the account for one or more subscriptions. Kill Bill supports the following billing periods: DAILY, WEEKLY, BIWEEKLY, THIRTY_DAYS, MONTHLY, QUARTERLY, BIANNUAL, ANNUAL, BIENNIAL or NO_BILLING_PERIOD
   
   [[Bundle]]Bundle:: A collection of subscriptions associated with a single service instance. For example, a customer might have a base subscription for her phone, plus an add-on subscription for international dialing. Because both subscriptions are associated with the same phone, they are collected into a single bundle. An account may have several bundles, each with one or more subscriptions. Also known as a "subscription bundle."
   
  
positive.code: 
  == X
  
  == Y
  
  == Z
  
negative.code: 
  == U
  
  Upgrade:: The change of a subscription from one plan to another plan of higher dollar value.
  
  User:: A person who logs on to Kaui.
  
  == V
  