What are these confusing measurements

Hello everyone, I wanted to know what are these measurements that everyone is talking about when they say BPEL and nbpel. Forgive me if I missed reading something, if I did can someone please post to me where I can read what these measurements are? Also I would like to know more about the LOT theory. It was way to confusing for me when I was reading it. I would like to know how do I measure LOT and is it really helpful to know. Thank you everyone please help me I’m eager to learn.

Use the search button for the LOT theory. BPEL= bone pressed erect length, and NBPEL= non bone pressed erect length. The bone pressed measurement is the total length measurement of the top of the penis until the ruler or measuring device touches the pubic bone.