The NEC has two sets of rules for the minimum size of feeder conductors. There’s one set for feeders not over 600V [215.2(A)] and another for those over 600V [215.2(B)]. Each subsection is broken into three sub subsections.
While (A) has no text associated with it, (B) provides eight lines of text about the ampacity of the conductors.
• The first subsection of (A) is titled General. It provides four lines about the ampacity of the conductors, ending in a choice