Punctuation

Q. I know semicolons are mandated for complicated lists. But is a complicated list defined only as a list containing commas within the items in the list?

A. Although items in a complicated series may well contain commas, the items can be complicated in other ways—for instance, they might have dashes or parentheses or a series of nouns connected by and or or.

[This answer relies on the 17th edition of CMOS (2017) unless otherwise noted.]