[nabs-l] Nemeth Code Question

[Miso Kwak]

Hi NABS,
Asking this on behalf of a friend of mine who is probably not 
subscribed on to this listserve at the moment. He asked me and I 
couldn't give him an answer.
In Nemeth code, what does 4, 3, 4, 6 mean?
Is the dot 4 in front of the plus sign make any difference?
Also, is there any Nemeth reference available in hard copy or as an 
electronic file?
Thank you in advance.
Best,
Miso Kwak