diff --git a/project_structure.md b/project_structure.md
index ec963b7..f268b8b 100644
--- a/project_structure.md
+++ b/project_structure.md
@@ -22,6 +22,9 @@ The complexity scores are rough estimates, but are useful in realizing how compl
 
 If your project is simple, do not add unnecessary structure.  This increases the cognitive load of anyone trying to use the project.
 
+### Organize Code by Responsibility
+
+
 ### Package `internal`
 
 ### Package `pkg`
@@ -36,3 +39,4 @@ Just as structs, funcs, files, packages, and modules are
 
 ### Other Resources
 
+https://rakyll.org/style-packages/
\ No newline at end of file