Custom “Enter Password” page per shared folder

For a special project I need the people I share a link with to agree on some “license”. Therefore I wonder if I can change the appearance of the password entry page for only one shared folder by placing a special file in the folder. It does not have to be the password page, it could as well (or even better) be a separate page where the downloader has to click an “accept” button.

Some details: I use ownCloud a lot for sharing private photographs with the grandparents of my son etc. From time to time I operate a photo booth on private parties. I would like to share the photos from these events as well. While the parties are private, there are many guests I do not know personally (e.g. on the court festival of my parent in law, where more than 100 people are joining every year). Therefore I would like to make these people to agree on some terms, e.g. that photos are only shared on social media if the depicted people are aware and agree. These terms I would like to write in a special file in the directory where the photos are located, and every time the folder is accessed via the public link, the password page or an additional page should show the terms so that people have to agree before they can access the files. Ideally, allowing Markdown syntax would be possible in this file.

This special file handling is, e.g., very similar to the handling of readme files on github.

Is this already possible with ownCloud? If not, what has to be done to make it possible? I am not a dev, so simple solutions preferred :wink:.