diff --git a/docs/handbook/image-file-formats.rst b/docs/handbook/image-file-formats.rst
index d265561de..af2c7171d 100644
--- a/docs/handbook/image-file-formats.rst
+++ b/docs/handbook/image-file-formats.rst
@@ -767,6 +767,13 @@ PIL reads and writes X bitmap files (mode ``1``).
 Read-only formats
 -----------------
 
+BLP
+^^^
+
+BLP is the Blizzard Mipmap Format is a texture format used in World of
+Warcraft. Pillow supports reading ``JPEG`` Compressed or raw ``BLP1``
+images, and all types of ``BLP2`` images.
+
 CUR
 ^^^
 
diff --git a/docs/releasenotes/5.1.0.rst b/docs/releasenotes/5.1.0.rst
new file mode 100644
index 000000000..e87bba3cb
--- /dev/null
+++ b/docs/releasenotes/5.1.0.rst
@@ -0,0 +1,36 @@
+5.1.0
+-----
+
+New File Format
+================
+
+BLP File Format
+^^^^^^^^^^^^^^^
+
+Pillow now supports reading the BLP "Blizzard Mipmap" file format used
+for tiles in Blizzard's engine.
+
+API Changes
+===========
+
+Optional channels for TIFF files
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Pillow can now open TIFF files with base modes of ``RGB``, ``YCbCr``,
+and ``CMYK`` with up to 6 8-bit channels, discarding any extra
+channels if the content is tagged as UNSPECIFIED.  Pillow still does
+not store more than 4 8-bit channels of image data.
+
+Append to PDF Files
+^^^^^^^^^^^^^^^^^^^
+
+Images can now be appended to PDF files in place by passing in
+``append=True`` when saving the image.
+
+Other Changes
+=============
+
+WebP memory leak
+^^^^^^^^^^^^^^^^
+
+A memory leak when opening ``WebP`` files has been fixed.
diff --git a/docs/releasenotes/index.rst b/docs/releasenotes/index.rst
index 0ee853fca..ab7b09785 100644
--- a/docs/releasenotes/index.rst
+++ b/docs/releasenotes/index.rst
@@ -6,6 +6,7 @@ Release Notes
 .. toctree::
   :maxdepth: 2
 
+  5.1.0
   5.0.0
   4.3.0
   4.2.1