From Red Hat Customer Service (CS Ticket 89521):

the use of the CRMFPopClient command at:
https://access.redhat.com/documentation/en-US/Red_Hat_Certificate_System/9/html/Command-Line_Tools_Guide/CRMF_Pop_Request.html

There is a call out NOTE which says:

'Key archival is done automatically based on whether a transport.txt file (containing the KRA's transport certificate) is in the directory from which the command is run. If the file is present, then the archival is automatically performed; if it is not, then no archival is attempted.
The transport.txt must have the entire base 64-encoded transport certificate on a single line with the header and footer removed'.

Based on our testing the description is incorrect. If the transport.txt file is not present, the archival is attempted anyway and fails with the message:
ERROR: File 'transport.txt' does not exist<br>
Try 'CRMFPopClient --help' for more information.

Please change the documentation to reflect this or fix the product. As it stands it is inaccurate and misleading.