Explanation
An installment can meet the selection criteria of a payment process request, yet not get selected for payment for one or more reasons.
You can review installments that were not selected for payment, along with the reasons they were not selected, on the Not Selected tab of the Review Installments page.
The reasons are as follows:
References:https://docs.oracle.com/cd/E37017_01/doc.1115/e22897/F438410AN16238.htm

Explanation
Oracle Fusion Expenses provides reimbursement functionality that ensures corporate card issuers and employees are reimbursed for business expenses. Expenses uses Oracle Fusion Payables to process expense reports for reimbursement. To reimburse card issuers and employees, the expense auditor runs the Process Expense Reimbursement process and the corporate card administrator runs the process, Create Corporate Card Issuer Payment Requests. After payment requests are created in Payables, corporate card issuers and employees are paid by Oracle Fusion Payments.
Thisfigure shows the flow of data when the expense auditor runs the Process Expense Reimbursement program.

Explanation
Conversion rate behavior applies only to cash expenses, not to corporate card expenses.
References:https://docs.oracle.com/cd/E60665_01/financialscs_gs/FAIEX/F1456644AN125F2.htm

Explanation
With Oracle Fusion Functional Setup Manager you can:
References:https://docs.oracle.com/cd/E56614_01/common_op/OAFSM/F1166427AN1007E.htm

Explanation
User-Defined Validation That Checks a Specific Condition and Value

References:https://docs.oracle.com/cloud/farel9/financialscs_gs/FAIPP/F1469799AN17B6B.htm