Update README.md

README.md

@@ -91,6 +91,10 @@ pretty_name: MedDistant19
 MedDistant19 is a more accurate benchmark for broad-coverage distantly supervised biomedical relation extraction that addresses these shortcomings and is obtained by aligning the MEDLINE abstracts with the widely used SNOMED Clinical Terms knowledge base.
 For more details, please refer to the paper: https://aclanthology.org/2022.coling-1.198/
 
+**Before Downloading**: To use this data, you must have signed the UMLS agreement. The UMLS agreement requires those who use the UMLS to file a brief report once a year to 
+summarize their use of the UMLS. It also requires the acknowledgment that the UMLS contains copyrighted material and that those copyright restrictions be respected. 
+The UMLS agreement requires users to agree to obtain agreements for EACH copyrighted source prior to its use within a commercial or production application. See https://www.nlm.nih.gov/databases/umls.html
+
 
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