Hi Mark,
Can you please clarify if you are referring to the Annual Total Cost of Capital% field that appears on the Financial Management Defaults page under the Administration>Finance>Setup menu? If yes, then you can find some information about this field in the Set Capital Cost and Reinvestment Rate for the System topic under "Create Financial Summaries" at the following docops sites:
Create Financial Summaries - CA PPM - 14.3 - CA Technologies Documentation
Create Financial Summaries - CA PPM SaaS - 14.3 - CA Technologies Documentation
Let us know if this information does not answer your questions adequately. I am also following up on this with SMEs and will get back to you with any further details that I can find out.
Regards,
Sarmistha