diff --git a/.gitignore b/.gitignore
index 1f6ae2c9..bcb72f9e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,7 +12,9 @@
 
 # build output:
 
-data/
+data/language-subtag-registry
+data/ucd
+
 src/libucd.la
 tests/printucddata
 
diff --git a/Makefile.am b/Makefile.am
index 9a10c624..1fecc915 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -58,7 +58,6 @@ UCD_VERSION=@UCD_VERSION@
 UCD_ROOTDIR=data/ucd
 
 data/language-subtag-registry:
-	mkdir -pv data
 	wget -O $@ http://www.iana.org/assignments/language-subtag-registry
 
 data/ucd/PropList.txt:
diff --git a/supplemental/Klingon.txt b/data/csur/Klingon.txt
similarity index 100%
rename from supplemental/Klingon.txt
rename to data/csur/Klingon.txt
diff --git a/data/csur/README.md b/data/csur/README.md
new file mode 100644
index 00000000..eb349bf7
--- /dev/null
+++ b/data/csur/README.md
@@ -0,0 +1,7 @@
+# ConScript Unicode Registry (CSUR)
+
+This folder contains data from the [CSUR](http://www.evertype.com/standards/csur/)
+in a form that is parsable by Unicode Character Database tools.
+
+Currently, the following table data has been defined:
+  *  [Klingon](http://www.evertype.com/standards/csur/klingon.html) [F8D0-F8FF]