I’ve never heard of it. I found same basic info on Wikipedia.
It seams to be a rather proprietary system.
<pre>JUMP is commonly used today as a proprietary method of capturing data from legacy systems. JUMPs modular format and consolidated views are an ideal tool for assembling legacy data in an easily reusable format. It is often used as an internal standard for documenting technical metadata across multiple projects. Based on need and requirement it has been modified and adapted across different organizations and industries.</pre>