What it means
A short markdown file served at yoursite.co.uk/llms.txt, listing what your business does and linking to the pages worth reading. It is a proposed convention rather than a standard anybody is obliged to honour, and support across assistants varies.
Why it matters to a small business
It costs about twenty minutes and it is the one place you get to state your own summary in your own words, instead of leaving an assistant to infer your business from whatever your homepage hero happens to say. For a business whose site is heavy on images and light on text, that inference often goes badly.
The bit people get wrong
Treat it as a bonus, not a strategy. Nothing is required to read it, and a site that blocks AI crawlers or hides its content behind JavaScript has a much bigger problem that an llms.txt will not touch. Fix the door before you write the sign.
Source: The llms.txt proposal. This page is a plain-English summary written by the Marketeer team, not legal advice. Where money or the law is involved, read the source.