Right-click a Callout and pick Info card for a small card: the first line
is its title (a clock, info, warning, bulb or tick emoji at its start is
drawn as a line icon), a line with a | is a row with the label on the left
and the value on the right, a row in bold is drawn in teal, and small
print is a grey line. An empty note starts with sample text.
The card look is a node property and the text is the note's own text, so
an Info card saves as a plain Callout: an older pack shows the same text
as a note with its rows written out. A plain callout never reads | as a
row, so no note written before changes.