broadly speaking, <front> ,<body> and <back> look the same. However, at their end, they vary: <body> uses
model.divBottom ("groups elements appearing at the end of a text division"), while <front> and <back> use
model.divBottomPart ("groups elements which can occur only at the end of a text division"). In fact, one encompasses
the other, which is sort of OK (though the descriptions are then confusingly similar), but the effect is that
all of the following: "meeting byline dateline argument epigraph salute docAuthor docDate" can only occur
at the end of <body>, not of <front>. Its hard to defend this.
EEBO A12096 (STC 22399) has an example of an epigraph (conveniently labelled "Epigramma de Miraculis Antichristi.") at the end of its (clear) <front>
Unfortunately, there is not a simple solution. These content models are horribly complicated. <front> has no mandatory content at all, so ambiguous content models result only too easily.