contributing - draft LLM statement

Author: jeremylt

CONTRIBUTING.md

@@ -44,6 +44,15 @@ By making a contribution to this project, I certify that:
 
 (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.
 
+## LLM Generated Content
+
+libCEED is a research software project, and such requires citation of the origin of ideas, as is expected with research papers.
+We expect all contributions to adhere to the Developer's Certificate of Origin.
+
+LLM generated code can contain novel algorithms replicated without attribution from training data.
+As such, we cannot accept pull requests containing code predominately generated by LLM.
+Pull requests should disclose and describe all LLM usage so project maintainers can work with the author to determine if the LLM usage is consistent with professional practices for citation needed for scholarly works.
+
 ## Authorship
 
 libCEED contains components authored by many individuals.