Every screen in Finance Enterprise has a screen mask that represents the module/folder that it is located in. You can type these masks in the search, press enter, and be taken directly to the page.
To see all the modules/folders/screen you have access to you can click on the Main Menu from any workspace.
PO represents that Purchase Order Module
UP Represents a folder of screens that will Update items
PR represents Purchase Requests
AP Represents the Accounts Payable Module
OH represents the Open Hold folder
IN represents the Invoice Processing folder
IN represents the Invoice Entry screen.