Text watermarking is a technique for embedding hidden information within textual content to verify its authenticity, origin, or ownership. [1] With the rise of generative AI systems using large language models (LLM), there has been significant development focused on watermarking AI-generated text. [2] Potential applications include detecting fake news and academic cheating, and excluding AI-generated material from LLM training data. [3] With LLMs the focus is on linguistic approaches that involve selecting words to form patterns within the text that can later be identified. [1] The results of the first reported large-scale public deployment, a trial using Google's Gemini chatbot, appeared in October 2024: users across 20 million responses found watermarked and unwatermarked text to be of equal quality. [3] Research on text watermarking began in 1997. [1]