What are Riser boards and partial server boards considered?

I'm having a hard time determining how to sort server riser boards and other misc boards inside servers, typically they have multiple PCIe type connectors or other high grade components so should be higher than a pcie card but no cpu sockets so not really a motherboard. Also some servers don't really have a normal motherboard but might have small risers for CPUs, separate risers for memory, and a few small "motherboards" for PCI and connectors to risers. We have about 100 servers like these and don't want to be ripped off by scrapyard if they price as low grade board.

Take some time to read through the e-waste materials sent to your inbox when you first signed up or in the ewaste section of this forum. Three is *a lot* of useful information there. Different buyers/yards have different grading systems but those guides will help you at least make basic sorting process by recovery value. If you have questions about specific boards post pictures and folks will get back to you.

I googled and 'Risers' & 'Backplanes' seem to be the same thing except Backplanes might be bigger & have a component or two on them.

I know what you mean though Eagleice, 'Backplanes' with some nice Yellow Tantis on them & a few IC's.