diff --git a/README.md b/README.md
index e840120..cc5c284 100644
--- a/README.md
+++ b/README.md
@@ -2,10 +2,22 @@
 
 The monorepo for all things CS50x in one place.
 
+## Linked subtrees
+
+* [`codespace`](./codespace) ([original repo][code50]) - environment customizations for [cs50.dev]
+* [`profile`](./profile) ([original repo][profile]) - profile readme for CS50x-specific GitHub account
+
 ## Utility tools
 
 * [`subtree50`](./scripts/subtree50) - manage CS50x subtrees in the monorepo
 
 ## License
 
-MIT
+Unless otherwise specified:
+
+* MIT for code
+* CC-BY-SA-4.0 for docs and Markdown files
+
+[code50]: https://github.com/code50/219805467
+[profile]: https://github.com/andreijirohdev-cs50x/andreijirohdev-cs50x
+[cs50dev]: https://cs50.readthedocs.io/cs50/codespace/