Obsidian does nothing of the sort. That is standard MD.
Obsidian (and others) use [[MyPage]] to create a link to MyPage (as does DT). Obsidian devs decided to extend that syntax to say if there is a ! prepended then display the item vs. create a link, borrowing from the MD syntax.
[MyImage](http://myserver/MyInage.jpg) would create a link to image and
![MyImage](http://myserver/MyInage.jpg) displays it.
There isnt a standard transclusion syntax for Markdown. There is a standard image syntax which Obsidian does support because it uses CommonMark. But Obsidian lets you transclude multiple file types like images, PDFs, etc.
There isnt a standard transclusion syntax for Markdown.
We use MultiMarkdown, so yes there is a standard we employ.
MultiMarkdown is not a standard, its superset. If there is any standard its the original/CommonMark.
There is an additional resource comparing markdown implementations at Implementations · markdown/markdown.github.com Wiki · GitHub
It doesn’t have descriptions of syntax, unfortunately, but the list of parsers and implementations may be useful nonetheless.
I believe @jasonekratz is correct: there is no true standard for Markdown syntax, and MultiMarkdown is a dialect or derivative (and mostly just one person’s idea of a direction to take). Efforts to standardize Markdown have been drawn out and controversial, and Gruber seems to dislike the current efforts (c.f. Standard Markdown Becomes Common Markdown then CommonMark).
There is an IETF RFC to standardize the media type for markdown (RFC 7763), and another titled “Guidance on Markdown: Design Philosophies, Stability Strategies, and Select Registrations (RFC 7764)” that discusses a number of Markdown variants; however, these documents are not standard specifications – they are “for informational purposes”.
The Wikipedia page for Markdown has some relatively up-to-date information on the general topic and state of affairs.
Regardless of Gruber’s feelings on it, he essentially defined a loose standard the moment he defined his schema.
And MultiMarkdown has often been seen as a natural extension of the original spec, while honoring the core he defined.
That was a helpful post - thanks!
After some digging I found the working combination in Obsi (not sure if that is the idea one but i works on both ends).
With a recent feature in DT allowing to configure a central location for images this works like magic now in both apps.
The relative path to file setting in Obsi makes this syntax readable by DT3 but also but any other md app.
Ah, and this plugin https://github.com/agathauy/wikilinks-to-mdlinks-obsidian solved the issue of [[wikilinks]] for internal links vs md links for images (with use [] disabled in Obsi).