The story
The standard of identity is from the Code of Federal Regulations, title 27, section 4.21(g).
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: Grape wine, mixed with brandy or alcohol, with natural flavors (including herbs), and optionally with caramel for color, that matches the general description of aperitif wine but not of vermouth. Full definition →
The standard of identity is from the Code of Federal Regulations, title 27, section 4.21(g).
Etymology from Wiktionary, CC BY-SA 4.0.