I would like to ask about certain features in problemsetting with CF and Polygon that I was not able to figure out how to use (or not even sure if they are supported at all). Probably some of them deserve feature requests.

SVG images in problem statements

Scalable Vector Graphics is a nice format to draw simple images and schemes that can be very lightweight and can be intergated directly into HTML page.

Now if you include SVG image with

\includegraphics[scale=1]{a.svg}

it will be substituted with PNG version of the image in HTML and will fail to build PDF with

LaTeX Error: Cannot determine size of graphic in a.svg (no BoundingBox).

What am I doing wrong?

Animated GIFs in problem statements

Providing animated example is a great way to explain processes that are described in the problem. Providing an external link to GIF feels somewhat inconvenient.

Now if you include animated GIF with

\includegraphics[scale=1]{s.gif}

it tries to substitute it with PNG image, but the link is broken and it renders missing image in HTML.

Is it possible to make it work?

Custom HTML / JS in problem statements

If problems statement is just an HTML page it can be cool to enhance it with static frontend JS-based application that can play animations or provide interactive examples for participants. Especially for education purposes.

Yes, an ability to include user-written JS script can be a serious security issue, but in some way you have trust the contest author anyway.

Ghosts in gym standings

Ghost participants of past competititon is a really cool feature. I'm planning to add some contests from different platform to the CF gym, and I would also like to export ghosts data for them. But how to configure ghosts for a mashup? What format does it use?

I've only found Export the judgment log to DAT-file section with Ghosts checkbox, but this is not the way to include it.

Different LaTeX or different examples for HTML and for PDF outputs

When problem statement is going to be used in both ways in HTML and in PDF, it is very annoying when you would like to make them a little different in layout. For example long lines in input/output examples are perfectly fine in HTML version, but will not fit into default PDF layout and it is good to provide custom input/output data for it, but only in PDF.

Also PDF and HTML statements are rendered differently and some LaTeX can work in one of them, but break the other one.