Don't you Victorians try the web. As an example:
Beef Primal Cuts - Medial View
Brisket is prepared from a 13 rib Forequarter by a straight cut which commences at the junction of the 1st rib and 1st sternal segment to the reflection of the diaphragm at the 11th rib and continuing to the 13th rib. All bones and cartilage are removed. The fatty tissue medial to the pectoral muscles is removed. The white fibrous tissue on the ventral edge (linea alba) is removed.
BRISKET POINT END
Brisket Pieces are prepared from a Brisket Point End and/or Navel End after removal of the Deckle (M. serratus ventralis). Brisket Pieces can comprise any or all of the muscles that comprise the Brisket.
The required pieces/portions are trimmed as specified between the buyer and seller.
BRISKET POINT END (DECKLE OFF)
Brisket Point End Deckle Off is prepared from a Brisket by the removal of the Navel End portion following the caudal edge of the specified rib. The Deckle is removed from the Point End along the natural seam together with associated fat and intercostals. The fatty tissue located between the pectoral muscles is completely removed.
BRISKET NAVEL END
Brisket Navel End is prepared from a Brisket by the removal of the Point End and following the caudal edge of the specified rib.