From: http://alpine.x10host.com/alpine/info/fillpara.html
Upstream: constitutes upstream source, delivered in non-tarball form

When you reply to a message, which has been quoted by several people and you
justify a paragraph, Alpine may not notice any other quote strings and justify
the paragraph as if there was no other quote strings in it. This patch will
help Alpine recognize extra levels of quoting, so that justifying will still
make the text readable. This is important because the purpose of justification
is to make the text more readable, and an incorrect justification may make the
text impossible to read.