I don't think my question should have been migrated. I'm asking a sports equipment question, not a physics theory question. I would compare my question to "what is a typical PSI of a football used in the NFL?" Surely sports and physics are related, but my question was not physics related, but rather just asking about specifications of a piece of sport equipment.
The reason: expertise.
As I state, I understand your question was in reference to equipment used in the sport of climbing. However, you seem to ask what elongation specifies a dynamic climbing rope and a static climbing rope. The expertise on Physics SE, compared to Sports SE, I felt would better help you clarify that discrepancy.
For example, if you asked which climbing rope, static or dynamic, is better suited for [condition: sharp rocks, smooth rocks, wet rocks, etc.]...it would line up more with the expertise on Sports SE. There is some overlap...perhaps this question may also be in the line of expertise offered by The Great Outdoors.
In addition, "What is a typical PSI of a football used in the NFL?" is 8.6-15.7 psi. It comes down to expertise. For example, I would not go to a sports statistician and ask him about the optimal tire pressure for the racetrack I race on.