In the 2002 NEC article 408 (old article 384) added the requirements of UL Std. 67 that only one grounded conductor can be terminated per terminal even if the terminal is identified for more than one conductor.
The other day I made up a new 100A Square D 3ph 4W panel board that had fed through lugs to supply another panel off the same 100A main breaker. The neutral lug supplied to terminate the grounded conductor for the feeders was a single lug rated for two conductors. No other place to terminate the #2 AWG grounded conductors. It seems odd that since this has been a requirement of UL for a long time that Square D would produce something that is in direct violation of this standard. [Linked Image]