Please bare with me and read this paragraph entirely, thank you.
As I need a little bit of automation to avoid working on this 24/7, I've thought for a relatively long time about the better way to filter participants, ( obvioulsy those who are not respecting the rules ), and I've come to the conlusion that email is the only sensible way.
I was hesitating between IPs and emails to "check" participants, and it appears to me that IP was too much valuable (in case of a server breach), and at the same time totally irrelevant considering many users are sharing IPs. So I choosed emails. I don't think this is invasive because it's quite easy to create aliases nowadays, and I strongly encourage you to create one specially for this website.
That way, in case this website get hacked (I hope not), there won't be anything of value to steal, because if your alias starts to get spam you just have to delete it :)
Regarding sending email, as I don't plan to send the topics via email at the present time, the only email you will receive from the website is the one with the code for your first participation. After that, you won't receive anything. A code, not a link (if you receive a link to something, that's not coming from here so don't click on it !)
To conclude the email paragraph, please do not participate with emails from outlook / hotmail / aol, as their email server are not standards compliant and they're deleting every email that are not coming from big companies. Even if I don't like gmail, at least they have the "courtesy" to send them to the spam folder...
And of course, don't use disposable emails... that's obvious, but sometimes even obvious things need to be emphasized.
A lot of email providers are offering alias options, and I strongly encourage you to use them in your everyday internet life.
Among them: Mailo, Yahoo, laposte... My favorite is mailo.
Outlook aliases are efficients, but as they suck with their server config, let's avoid them.
Gmail is offering something that looks like an alias, but that's not a real one as it's created from the name of your real account, so it's easy to re-create your main address. Not a good choice if you want to keep your main email "private".
Or you can use your own domain name and pay for a real email services provider, but as that's not free, not many will go down this road (even if the above services are not free either, it's just that you don't know precisely how much you pay for them... ;)
iFRAMES (link-viewer) :
The link-viewer section is using what is called an "iframe". It's the part of this website where there's a window open to another website. Cool, right ? It was already like this on the original website.
BUT (and it's a big BUT), iframes can bring some security issues, so it's not unusual to see them blocked with something called "CSP" (content security policy). I have checked with some big plateforms like blogger or wordpress.com for instance, and it seems that it's still working with them so far, but I can neither guarantee that it will work with other hosting solutions that I haven't tested, nor that it will forever with the aforementioned ones. Obvioulsy, if you're managing your server you already know about this so you can decide for yourself if you want to add this domain to your CSP "whitelist" or not. (if CSP is active)
Anyway, all things considered that's still the best/more comfy solution for the link-viewer, so I intend to keep it that way :)
Remember that when you click on a link, that's a page on another website that is loading, so don't be in a hurry. Even though it's plenty quick enough for normal people, it won't sustain a frenzy of clicks. Thank you for your understanding.
You need to upload thumbnails that are exactly 70 x 70 pixels, or your participation will not be entered.
This is pretty easy to do, and you can do that with free softwares like XnviewMP (available on most computer OS). I can only recommend something for android (Resize Me! or snapseed) as I don't have access to an iphone.
A word about websites that you can use to participate : nearly everything that you can imagine is OK as long as the website where the URL is pointing is "yours". I mean, you don't need to pay for a hosting service, but the website must at least reflect your work / who you are and not be visually the same thing used by millions of people (like social networks...).
So, posting links to instagram, twitter, facebook (etc) is not tolerated.
Social networks pages are not intended as galleries, and your "page" there looks like every other page : it doesn't have any personnality. So it's better to use a proper website or at least create a blog on some shared publishing services that allow theming like blogger, wordpress.com, and the list can go on but I don't know every one of them ;)
Plus, the intention here is not to increase the already enormous data collection and income of these humongous platforms, so the only social networks that are tolerated for a participation are the ones that are parts of the fediverse ;) But the previous remark regarding personnality is still valid for the fediverse.
Also, the big social network players often ask for registration to browse their content correctly, so that wouldn't be usable here anyway.