The Rules
The Rules section of the panel holds the typesetting decisions. The defaults suit most documents; here is what each one does and when to change it.
Keep with next
A regular expression matched against block layer names, case-insensitively. A matching block never ends a page: it moves to the next page together with the block after it. Any block whose name contains [keep] matches regardless.
^(h[1-6]\b|heading|title)The default matches "H1 Title", "h2 Section", "Heading", "Title". Add your own names with a pipe: ^(h[1-6]\b|heading|title|caption|label).
Splittable tag
A block whose layer name contains this tag, and which is itself a vertical auto layout, may break between its children. The first part stays, the rest continues on the next page in a copy of the same frame. If the first child is named "Header", it is repeated at the top of the continuation.
[split]Split paragraphs between lines
When on, a text block that does not fit breaks at the end of the last line that does. Styles stay on both parts, the whitespace at the break is remembered, and Reflow joins the parts back before it paginates again. When off, text blocks move whole like everything else.
Smallest part, in lines
Neither part of a split paragraph may be shorter than this. The default of two prevents a single line stranded at the top or bottom of a page. A paragraph that cannot satisfy it moves whole.
Gap between pages, and layout
Where page instances are placed on the canvas: in a row or a column, with this gap. Changing it affects new flows and the next Reflow.
Remove the source frame
On by default. Turn it off to keep the empty frame as a marker of where the document came from.
Rules live in layer names
Set a block’s name once in the source frame and the rule travels with it through every flow and reflow. The regex and the tag in the panel only say how names are read.