Anthropic says text and files generated by Claude will carry a model-level watermark using the open C2PA standard, and it stays even after copy-paste or light editing. It is being rolled out to comply with the EU AI Act, which took effect on 2 August. Newer models get it first, older ones later; the article does not say how many edits remove it. For a Thai SME, this matters only if you sell or publish content into the EU or use AI for customer-facing material. Start by checking whether your AI-written content (marketing, product descriptions, reports) needs a disclosure label for those markets.