@gsf: yes, you are right that it is unique to Obsidian. Having said that. and having had to transfer my notes a fair number of times, I must say that I am “addicted” to transclusions. It makes writing and compiling so much more pleasant and productive, not having to repeat texts.
If, for whatever reason, I would stop using Obs, the transclusion link text will point me to what I meant to transclude - makes sense 
Regarding the syntax, it is very easy, it’s like when you link to an image, which in effect is also an embed.
![[filename]] will show the file in Preview.
To transclude a header from another note: ![[filename#headername]]
To transclude a block (i.e. a paragraph) from another note: ![[filename^keyword]].
The block reference is slightly different. Let’s assume you have the following paragraph in note 1:
Dolor nulla modi in qui quibusdam in aperiam. Ab vero eaque qui vel voluptatem. Minima culpa cumque magni sunt et. Minima voluptatem facilis qui rerum. Ut dignissimos doloribus earum officia odit animi voluptatem. Nobis exercitationem mollitia sint enim eos doloribus itaque amet.
Now, if you want to transclude that para in note 2, you would have to do:
![[note 1^
and as soon as you type the caret (^) you’ll get a list of all the paragraphs in note 1. You can then start typing what I call a distinctive word that only appears in that para, in this case “quibusdam” (without the quotation marks).
Obsidian will then assign a unique ID number to that paragraph, e.g. 123ab45. So it will complete your transclusion syntax: ![[note 1^123ab45]]. That’s it.
Note that a paragraph is a block of text with an empty line above and below it.