How to Use "Expense Report Invoices" Document Sequence Category

Hi All,

We are considering to maintain separate document sequence for Expense Report Invoices. In that case, we can use the "Payment Request" document sequence category. However, there is another document sequence category as "Expense Report Invoices".

What will be the difference between these two categories and can we use this "Expense Report Invoices" category to maintain separate document sequence for expense report invoices?

Thank You,

KP