Links and images

Links

[KaTeX documentation](https://katex.org/docs/supported)
[with a tooltip](https://katex.org "Shown on hover")
<https://arxiv.org>

KaTeX documentation

Bare URLs in prose linkify on their own (GFM autolinks): https://arxiv.org/abs/1706.03762 becomes a link without any brackets.

External links open in a new tab automatically and carry rel="nofollow noopener noreferrer". Links within LibreTimes and fragment links to heading anchors open in place.

Allowed link protocols are https, http, and mailto. Anything else (javascript:, data:, custom schemes) is stripped during sanitization.

Reference links

For a heavily linked document, keep the URLs out of the prose:

The proof follows [Tao's notes][tao] and the [original paper][annfm].
 
[tao]: https://terrytao.wordpress.com
[annfm]: https://arxiv.org/abs/1706.03762

Definitions can sit anywhere in the document; by convention they collect at the bottom of the section that uses them.

Images

![Phase portrait of the pendulum](https://example.com/phase-portrait.png)
![With a tooltip](https://example.com/plot.png "Shown on hover")

The alt text in the brackets matters: it is what screen readers announce and what shows if the image fails to load. Describe the content, not the fact that it is an image.

Image sources must be https (or http) URLs. For images that belong to the publication itself, upload them as attachments in the editor rather than hot-linking – attachment images are served from LibreTimes storage and do not rot when an external site moves. To give an image a caption, wrap it in a figure.

A URL pointing at a YouTube or Vimeo page inside image or link syntax becomes a video embed, not an image.