- Tags are hex-encoded by replacing every byte not matching the
- regex <b>[A-Za-z0-9@=.,</b>_<b>+-]</b> with <b>%nn</b> where nn is the two digit hex
- encoding. The message ID is a valid Xapian query, quoted using
- Xapian boolean term quoting rules: if the ID contains white-
- space or a close paren or starts with a double quote, it must
- be enclosed in double quotes and double quotes inside the ID
- must be doubled. The astute reader will notice this is a spe-
- cial case of the batch input format for <a href='../notmuch-tag-1/'>notmuch-tag</a>(1); note
- that the single message-id query is mandatory for <a href='../notmuch-restore-1/'>notmuch-</a>
- <a href='../notmuch-restore-1/'>restore</a>(1).
+ 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.