Add DCO and instructions to CONTRIBUTING

1 files changed, 53 insertions, 3 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 789d778..16d6573 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -9,14 +9,64 @@ Do you enjoy working on obscure cryptographically secure time synchronization pr
 Please open a pull request (PR) for your changes and include:
 
 * An overall description/rationale of the PR
-* Tests for any new functionality
+* Tests for any new or modified functionality
 * Code formatted with `rustfmt` default style settings 
 * License (Apache 2.0) and copyright statements for your code
+* A Developer Certificate of Origin (DCO) sign-off as described below
 * A willingness to iterate and make changes ;)
 
 `Roughenough` targets **stable Rust** only. Contributions that don't compile
-on `stable` will be rejected. Sorry.
+on `stable` will be declined. Sorry.
 
-# Thanks In Advance
+# Developer Certificate of Origin
+
+To provide assurance of the provenance and integrity of contributions 
+Roughenough uses the [Developer Certificate of Origin](https://developercertificate.org/)
+created by the Linux Foundation instead of lengthy Contributor License 
+Agreements (CLAs). 
+
+Please include *verbatim* and *unchanged* the full DCO statement 
+below with your PR:
+
+```
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+1 Letterman Drive
+Suite D4700
+San Francisco, CA, 94129
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.
+```
+
+# Thanks In Advance for Helping Roughenough!
 
 Stuart @int08h