Add Attribution & takedown section

README.md

@@ -1150,3 +1150,21 @@ native_only = train.filter(lambda x: x["source_type"] == "native")
 ## License
 
 Apache 2.0
+
+## Attribution & takedown
+
+Portions of this dataset derive from publicly available code
+repositories (The Stack v2 for the English source subsets; public
+GitHub and Gitee repositories for natively-authored code), collected
+under a best-effort license review. If you are the author of code
+included here and believe it was included improperly, or you would
+like attribution added or your code removed:
+
+- open a discussion on this repository's **Community** tab, or
+- email Madi Edgar at **support@legesher.com** (the maintainer listed in
+  `CITATION.cff`).
+
+We commit to citing, and on request from authors removing, any source
+identified as improperly included. Removals are propagated in a new
+dataset revision; prior revisions remain in git history unless a
+takedown requires otherwise.