Royalty-free (RF) material subject to copyright or other intellectual property rights may be used without the need to pay royalties or license fees for each use, per each copy or volume sold or some time period of use or sales.
買斷式授權（英文：Royalty-free，縮寫：RF）用來宣告一項具有版權、專利或著作權的產品能（永久或特定時段）被使用而不需要支付權利金或執照費（License fee），即免版稅。
Abstract from DBpedia / Wikipedia · CC BY-SA
via Wikidata sitelinks · CC0
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).