REL: NumPy 1.16.6 release.

diff --git a/doc/release/1.16.6-notes.rst b/doc/release/1.16.6-notes.rst
index e99f55b..cda3449 100644
--- a/doc/release/1.16.6-notes.rst
+++ b/doc/release/1.16.6-notes.rst

@@ -8,6 +8,10 @@
 linked with OpenBLAS v0.3.7, which should fix errors on Skylake series
 cpus.
 
+Downstream developers building this release should use Cython >= 0.29.2 and, if
+using OpenBLAS, OpenBLAS >= v0.3.7. The supported Python versions are 2.7 and
+3.5-3.7.
+
 Highlights
 ==========
 

diff --git a/setup.py b/setup.py
index bcfd9c6..9546682 100755
--- a/setup.py
+++ b/setup.py

@@ -62,7 +62,7 @@
 MAJOR               = 1
 MINOR               = 16
 MICRO               = 6
-ISRELEASED          = False
+ISRELEASED          = True
 VERSION             = '%d.%d.%d' % (MAJOR, MINOR, MICRO)