i don't recall a definition of subpanel, methinks that's our own jargon.
that aside, there's much ado about where said 'subpanel' may be.
for instance a 'subpanel' can be withing the same structure, or in a satelitte structure
this becomes, imho, the point of definitional confusion
in the latter case,iirc, although it may be referred to as 'the barn subpanel' it will still fall under the auspices of the 'service entrance' doctrine within the nec...
~S~
