documentation and changelog

docs/administration.rst

@@ -20,6 +20,8 @@ Options available to any installation of paperless:
     metadata to a specific folder. You may import your documents into a
     fresh instance of paperless again or store your documents in another
     DMS with this export.
+*   The document exporter is also able to update an already existing export.
+    Therefore, incremental backups with ``rsync`` are entirely possible.
 
 Options available to docker installations:
 
@@ -157,8 +159,13 @@ backup or migration to another DMS.
 
 .. code::
 
-    document_exporter target
+    document_exporter target [-c] [-f] [-d]
 
+    optional arguments:
+    -c, --compare-checksums
+    -f, --use-filename-format
+    -d, --delete
+    
 ``target`` is a folder to which the data gets written. This includes documents,
 thumbnails and a ``manifest.json`` file. The manifest contains all metadata from
 the database (correspondents, tags, etc).
@@ -167,6 +174,24 @@ When you use the provided docker compose script, specify ``../export`` as the
 target. This path inside the container is automatically mounted on your host on
 the folder ``export``.
 
+If the target directory already exists and contains files, paperless will assume
+that the contents of the export directory are a previous export and will attempt
+to update the previous export. Paperless will only export changed and added files.
+Paperless determines whether a file has changed by inspecting the file attributes
+"date/time modified" and "size". If that does not work out for you, specify
+``--compare-checksums`` and paperless will attempt to compare file checksums instead.
+This is slower.
+
+Paperless will not remove any existing files in the export directory. If you want
+paperless to also remove files that do not belong to the current export such as files
+from deleted documents, specify ``--delete``. Be careful when pointing paperless to
+a directory that already contains other files.
+
+The filenames generated by this command follow the format
+``[date created] [correspondent] [title].[extension]``.
+If you want paperless to use ``PAPERLESS_FILENAME_FORMAT`` for exported filenames
+instead, specify ``--use-filename-format``.
+
 
 .. _utilities-importer: