diff --git a/README.md b/README.md
index 111222a..cc7db7f 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,16 @@
 # add-missing-nan
 
+## Syntax
+
+```plaintext
+add-missing-nan.ps1
+    [-InputFile] <String>
+    [-OutputFile] <String>
+    [[-NaNString] <String>]
+```
+
+## Description
+
 This script is adding missing NaN values into XYZ stream.
 
 For some plotting tools it is necessary that the input data forms a uniform "net".
@@ -59,4 +70,11 @@ The output is sorted by the second row (as in the example).
 
 `-OutputFile`: Path to the output file
 
-`-NaNString`: String that used as z-value for missing x-y-pairs
+`-NaNString`: String that used as z-value for missing x-y-pairs (default: `NaN`)
+
+## License
+
+This code is licensed under the [UNLICENSE](UNLICENSE).
+So you can do wat you want.
+But ... I must admit, that I am bit curious.
+If you want, you can [leave a message](mailto:ar-std@mailbox.org?subject=add-missing-nan) and tell me what you are using the script for.
diff --git a/UNLICENSE b/UNLICENSE
new file mode 100644
index 0000000..68a49da
--- /dev/null
+++ b/UNLICENSE
@@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <http://unlicense.org/>