diff --git a/NOTICE.txt b/NOTICE.txt
index 0310c897cd743..a85101617cec8 100644
--- a/NOTICE.txt
+++ b/NOTICE.txt
@@ -7,3 +7,8 @@ The Apache Software Foundation (http://www.apache.org/).
 This product includes software from the SFrame project (BSD, 3-clause).
 * Copyright (C) 2015 Dato, Inc.
 * Copyright (c) 2009 Carnegie Mellon University.
+
+This product includes software from the Numpy project (BSD-new)
+ https://github.com/numpy/numpy/blob/e1f191c46f2eebd6cb892a4bfe14d9dd43a06c4e/numpy/core/src/multiarray/multiarraymodule.c#L2910
+ * Copyright (c) 1995, 1996, 1997 Jim Hugunin, hugunin@mit.edu
+ * Copyright (c) 2005 Travis E. Oliphant oliphant@ee.byu.edu Brigham Young University
diff --git a/cpp/src/arrow/ipc/metadata-internal.cc b/cpp/src/arrow/ipc/metadata-internal.cc
index dfb2ae2b7c58e..96168cbda824f 100644
--- a/cpp/src/arrow/ipc/metadata-internal.cc
+++ b/cpp/src/arrow/ipc/metadata-internal.cc
@@ -247,6 +247,7 @@ Status FieldFromFlatbuffer(const flatbuf::Field* field, std::shared_ptr<Field>*
 // Implement MessageBuilder
 
 // will return the endianness of the system we are running on
+// based the NUMPY_API function. See NOTICE.txt
 flatbuf::Endianness endianness() {
   union {
     uint32_t i;
diff --git a/format/Layout.md b/format/Layout.md
index 2efcdfd94cbbc..5eaefeebf210a 100644
--- a/format/Layout.md
+++ b/format/Layout.md
@@ -79,10 +79,10 @@ Base requirements
 ## Byte Order ([Endianness][3])
 
 The Arrow format is little endian by default.
-The Schema metadata has an endianness field indicating endiannmess of RecordBatches.
+The Schema metadata has an endianness field indicating endianness of RecordBatches.
 Typically this is the endianness of the system where the RecordBatch was generated.
 The main use case is exchanging RecordBatches between systems with the same Endianness.
-At first we will return an error when trying to read a RecordBatch with an endianness
+At first we will return an error when trying to read a Schema with an endianness
 that does not match the underlying system. The reference implementation is focused on
 Little Endian and provides tests for it. Eventually we may provide automatic conversion
 via byte swapping.