The 40% fill req. is more of a TIA/EIA req. rather than NEC req.
If you do tele/data, or CATV etc. you may want to check these out. They are not all of the standard in it's actual format, but seeing that the go for $200 bucks each, these trunkated versions/explanations are just fine. Also very informative.....
http://web.anixter.com/Anixter/anixter.nsf/Standards?OpenForm --------------------------------
Just looked at them again, the pages have changed, they used to have a lot more information on them before.
[This message has been edited by e57 (edited 10-11-2004).]
