What do you call "import script"? The import line? And why "without Processing IDE"? (which is called PDE, BTW).

Anyway, if you indicated which library you are talking about, we could be more precise...

But the generic information is that it actually reflects a folder structure! The structure of folders in the source code, which is copied when compiling, and packed in the jar file.
If you go, for example, to <processing install dir>/libraries/opengl/library, you will find an opengl.jar file (among others). If you open it in an archive software like 7-Zip, you will find a processing folder holding an opengl folder where there is a PGraphicsOpenGL.class file (and some others).
The processing/opengl/PGraphicsOpenGL.class directory structure is translated to processing.opengl.PGraphicsOpenGL or, to include several classes at once in this package, by processing.opengl.*

You can do a similar study on your mysterious jar file.

Thanks for the quick reply. I apologize for being so cryptic. I want to play around with  this library. I am using PDE, however when I place the files in the ~Documents/Processing/libraries it doesn't show up under the Sketch > Import Library drop-down menu. Your explanation makes a lot of sense. I'm gonna give it a try and post some findings.

—
http://jonobr1.com/

Ah, OK, I forgot Processing can generate automatically the include lines.

I downloaded the BaseKit to take a look, it is lacking a bit of information...
But I see the zip file has all the folders at the top level. So you have to unzip them to ~Documents/Processing/libraries/BaseKit for this one, etc. ie. in a sub-folder of same name as the .jar file.