No Maintenance Intended is a snippet of markup (or markdown) you can add to your site or app to ensure that users understand that they're on their own and can stuff right off if they think any work is going to get done for them. Same for would-be contributors and their annoying pull requests.
If you're here, that likely means a project linked you here.
Thanks so much for being interested in that project!
Open Source is rewarding but it can also be exhausting sometimes.