anchor.diff:  
   |===
   
  -External Payment::  A built-in payment method that can be used to track payments that occur outside of Kill Bill.
  -
  -Event:: A message exposed by Kill Bill core components that triggers certain system actions. For example, when a subscription is created, Kill Bill triggers an event that leads to invoice generation. 
  +External Payment Method:: A built-in payment method that can be used to track payments that occur outside of Kill Bill (example: check payments).
  +
  +Event:: A message exposed by Kill Bill core components when a certain occurrence takes place in the system. For example, when a subscription is created, Kill Bill generates an event corresponding to it.
   
   == F
   
  
positive.code: 
  //Account Balance:: TODO
  
  Account Credit:: The amount that your business owes to a customer. It is generated when an administrator adds a credit, a subscription is cancelled, etc. It is calculated as the sum of `CBA_ADJ` <<Invoice_Item, invoice items>>.
  
  
  == B
  
negative.code: Billing in Arrear:: A type of https://docs.killbill.io/latest/catalog-examples.html#_billing_modes[billing mode] in which you can charge for services that are delivered in a previous billing period.
  
  [[billing_start_date]]
  Billing Start Date:: The date on which billing starts for a subscription. See also <<entitlement_start_date, Entitlement Date>>.
  
  [[billing_mode]]
  Billing Mode:: The method in which you invoice for a recurring subscription. "Billing in advance" and "billing in arrear" are two types of billing modes.
  