Paste an address. The checker validates the page against the Mews DTD, reads your stylesheet and up to twenty images, and lists every rule it breaks with the section of the spec that explains it.
Check page reports and keeps nothing. Check and list also puts your site in the directory if the page passes. Either way it takes up to a minute, with no progress bar, because that would want JavaScript. Leave this page open and put the kettle on.
The same checks run on the command line, which is quicker while you are still fixing things:
uv run mewslint.py https://example.com/
It reads local files too, so you can check a page before publishing it. This site's own build refuses to produce mews.page if any of its pages stops conforming. That seemed only fair.
One page per site, the one you submit, and nobody reviews it: it passes or it doesn't. Listed sites are rechecked every week, and there is no address to warn you at. No account, no password to forget, and no warning either.
A page turned down over something the spec doesn't say is a bug in the validator, not a fault in your page. Report it to the address on the home page.