Reference https://docs.oracle.com/en/cloud/saas/applications-common/19b/facia/define-enterprise-structures.html#FACIA462453 Reference Data Sharing Methods Variations exist in the methods used to share data in reference data sets across different types of objects. The following list identifies the methods:
Assignment to one set only, no common values allowed. This method is the simplest form of sharing reference data that allows assigning a reference data object instance to one and only one set. For example, Asset Prorate Conventions are defined and assigned to only one reference data set. This set can be shared across multiple asset books, but all the values are contained only in this one set.
Assignment to one set only, with common values. This method is the most commonly used method of sharing reference data that allows defining reference data object instance across all sets. For example, Receivables Transaction Types are assigned to a common set that is available to all the business units. You need not explicitly assign the transaction types to each business unit. In addition, you can assign a business unit-specific set of transaction types. At transaction entry, the list of values for transaction types includes the following:
Transaction types from the set assigned to the business unit.
Transaction types assigned to the common set that is shared across all business units.
Assignment to multiple sets, no common values allowed. The method of sharing reference data that allows a reference data object instance to be assigned to multiple sets. For instance, Payables Payment Terms use this method. It means that each payment term can be assigned to one or more than one set. For example, you assign the payment term Net 30 to several sets but assign Net 15 to a set specific only to your business unit. At transaction entry, the list of values for payment terms consists of only the set that is assigned to the transaction,s business unit.
Note: Oracle Fusion Applications contains a reference data set called Enterprise. Define any reference data that affects your entire enterprise in this set. Also update the data set going forward as you create new reference data items.

Reference https://fusionhelp.oracle.com/helpPortal/topic/TopicId_P_8718794B26A7BB93E040D30A688149A3

Reference https://docs.oracle.com/cloud/latest/common/FASCC/FASCC1124283.htm Topic - Contract Actions and Status Changes: Explained

When the invoice is created, the unbilled receivables balance is reduced and the accounts receivables balance is increased by the invoice amount. This is because the revenue has already been recognized and the invoice is just a request for payment from the customer. https://docs.oracle.com/en/cloud/saas/project-portfolio-management/20c/oapfm/project-accounting.html#OAPFM2355710