MSC_SYSTEM_ITEMS table - what is FULL_PEGGING flag?

I currently have a production issue where supply that is on hand is being ignored by ASCP. It is collected, I see it in the planner workbench. For some reason ASCP is not viewing it as valid supply. I've done a lot of research comparing production to our test environments (where it is correctly pegging) and noticed that in production, the MSC_SYSTEM_ITEMS.FULL_PEGGING value is '3' where in test it is '1'.

I can't find documentation telling me where that flag is and how to change it. Nor do I have a test box where I can try it out!