.SH SYNOPSIS
.B "notmuch dump"
+.RB [ "\-\-format=(sup|batch-tag)" "] [--]"
.RI "[ --output=<" filename "> ] [--]"
.RI "[ <" search-term ">...]"
therefore the only critical thing to backup (and much more friendly to
incremental backup than the native database files.)
+.TP 4
+.B \-\-format=(sup|batch-tag)
+
+Notmuch restore supports two plain text dump formats, both with one message-id
+per line, followed by a list of tags.
+
+.RS 4
+.TP 4
+.B sup
+
+The
+.B sup
+dump file format is specifically chosen to be
+compatible with the format of files produced by sup-dump.
+So if you've previously been using sup for mail, then the
+.B "notmuch restore"
+command provides you a way to import all of your tags (or labels as
+sup calls them).
+Each line has the following form
+
+.RS 4
+.RI < message-id >
+.B (
+.RI < tag "> ..."
+.B )
+
+with zero or more tags are separated by spaces. Note that (malformed)
+message-ids may contain arbitrary non-null characters. Note also
+that tags with spaces will not be correctly restored with this format.
+
+.RE
+
+.RE
+.RS 4
+.TP 4
+.B batch-tag
+
+The
+.B batch-tag
+dump format is intended to more robust against malformed message-ids
+and tags containing whitespace or non-\fBascii\fR(7) characters.
+Each line has the form
+
+.RS 4
+.RI "+<" "encoded-tag" "> " "" "+<" "encoded-tag" "> ... -- " "" " id:<" encoded-message-id >
+
+where encoded means that every byte not matching the regex
+.B [A-Za-z0-9@=.,_+-]
+is replace by
+.B %nn
+where nn is the two digit hex encoding.
+The astute reader will notice this is a special case of the batch input
+format for \fBnotmuch-tag\fR(1); note that the single message-id query is
+mandatory for \fBnotmuch-restore\fR(1).
+
+.RE
+
+
With no search terms, a dump of all messages in the database will be
generated. A "--" argument instructs notmuch that the
remaining arguments are search terms.
.B "notmuch restore"
.RB [ "--accumulate" ]
+.RB [ "--format=(auto|batch-tag|sup)" ]
.RI "[ --input=<" filename "> ]"
.SH DESCRIPTION
The input is read from the given filename, if any, or from stdin.
-Note: The dump file format is specifically chosen to be
+
+Supported options for
+.B restore
+include
+.RS 4
+.TP 4
+.B \-\-accumulate
+
+The union of the existing and new tags is applied, instead of
+replacing each message's tags as they are read in from the dump file.
+
+.RE
+.RS 4
+.TP 4
+.B \-\-format=(sup|batch-tag|auto)
+
+Notmuch restore supports two plain text dump formats, with each line
+specifying a message-id and a set of tags.
+For details of the actual formats, see \fBnotmuch-dump\fR(1).
+
+.RS 4
+.TP 4
+.B sup
+
+The
+.B sup
+dump file format is specifically chosen to be
compatible with the format of files produced by sup-dump.
So if you've previously been using sup for mail, then the
.B "notmuch restore"
command provides you a way to import all of your tags (or labels as
sup calls them).
-The --accumulate switch causes the union of the existing and new tags to be
-applied, instead of replacing each message's tags as they are read in from the
-dump file.
+.RE
+.RS 4
+.TP 4
+.B batch-tag
-See \fBnotmuch-search-terms\fR(7)
-for details of the supported syntax for <search-terms>.
+The
+.B batch-tag
+dump format is intended to more robust against malformed message-ids
+and tags containing whitespace or non-\fBascii\fR(7) characters. This
+format hex-escapes all characters those outside of a small character
+set, intended to be suitable for e.g. pathnames in most UNIX-like
+systems.
.B "notmuch restore"
updates the maildir flags according to tag changes if the
details.
.RE
+
+.RS 4
+.TP 4
+.B auto
+
+This option (the default) tries to guess the format from the
+input. For correctly formed input in either supported format, this
+heuristic, based the fact that batch-tag format contains no parentheses,
+should be accurate.
+
+.RE
+
+.RE
+
.SH SEE ALSO
\fBnotmuch\fR(1), \fBnotmuch-config\fR(1), \fBnotmuch-count\fR(1),