diff --git a/Code-contribution-rules.md b/Code-contribution-rules.md
index 16f1117..637a706 100644
--- a/Code-contribution-rules.md
+++ b/Code-contribution-rules.md
@@ -17,4 +17,13 @@ It's important for everyone, be it contributors or reviewers, to have a clear co
 
 * PRs should be up to date with 'next'
 * Each new functionality should have it's own PR, don't put too much files/commits into a single PR. When it's too much commits, one can make a new branch and report only the modified files in a single commit, to make the review easier
-* Merging of any PR is up to the maintainers good will
\ No newline at end of file
+* Merging of any PR is up to the maintainers good will
+
+# which license of code is safe to use   
+ - MIT: It's safe to copy MIT license, as long as you keep original copyright info.   
+ - MPL: It's safe to copy MPL license, as long as you follow Mozilla's agreement.
+ - GNU: This project is under GPL which means it's safe to use GPL code here as long as you open source your the distro under GPL license.  
+ - The Unlicensed: safe to use.
+ - BSD: safe to use.
+ - WTFPL: Safe to use.  
+ - CC0: safe to use.