Update README.md

README.md

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 ## License
 
-[CC BY-NC 4.0](https://creativecommons.org/licenses/by-nc/4.0/) — Attribution–NonCommercial 4.0 International.
+This dataset contains material from multiple sources with different rights statuses.
 
-This dataset is released for **research and evaluation use only**. The non-commercial restriction reflects the uncertain upstream rights of some source material (historical newspapers from Switzerland and Luxembourg, where copyright status is not systematically documented). Do not use this dataset to train commercial models.
+- Part of the source material derives from the National Library of Luxembourg (BnL) OCR ground-truth release [`bnl-ground-truth-newspapers-before-1878.zip`](https://data.bnl.lu/wp-content/uploads/2021/07/bnl-ground-truth-newspapers-before-1878.zip), which the BnL describes as **CC0 / Public Domain**.
+- Additional original contributions made by the dataset creators in this release — including curation, selection, cleaning decisions, split construction, and documentation — are made available under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).
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+Users should therefore distinguish between upstream source material, which remains available under its original terms, and original contributions in this release, which are provided under **CC BY 4.0**.
+
+This dataset is intended primarily for **evaluation use**. Do not train models with it! Users remain responsible for assessing the rights status of any upstream source material, especially where historical newspaper provenance or copyright status is not fully documented across jurisdictions.
 
 If you use this dataset, please cite the [Impresso project](https://impresso-project.ch/) and link to this repository.