Recently I discovered the feature to move lines of text up and down, Edit > Swap line down / Swap line up. It's so helpful, but somehow I missed it all this time.
What's your favorite "hidden" feature of Joplin?
Disclaimer!
Edit: Please take "hidden" very broadly. If you feel inspired to post, then it surely will be hidden for someone. I've already learned lots. Just because a feature can be found in the documentation doesn't disqualify it from being hidden. Because who reads documentation!
It's not really a "hidden" function but I love GoToAnything (Ctrl-P) for searching. Example
tag:home tag:lisa math
This allows you to quickly search for notes with the tag "home" and "lisa" and including the word "math". It is much more responsive than the standard search. On the other hand, it's really not practical that you can't keep this search open (or go back quickly in the search history as in a terminal) when you want to search in several notes that you have to read.
Actually, I feel like the go to anything is a hidden feature when you compare it to the visibility of the search in the sidebar. It took me a while to find it and now that's all I use.
The customizable shortcuts option in the terminal application: Joplin | Joplin. I basically have shortcuts like dd to delete the current item, ss to trigger sync, etc!
hiddenness of this is debatable but I recently discovered that Joplin does render local image links if you put it like an image link . So all you need to do is while holding down Alt, dragging the file to the note (this creates a link) and then add a ! to the beginning to indicate it's an image. This is great for me because I only use the Desktop version and I backup my files to an external drive. I don't need to clutter my cloud storage. But obviously you need to keep the same folder structure for the links to work after a fresh install.
Definitely not a hidden feature, but after Evernote's rigid attitude about notebooks I was almost literally dancing with joy that Joplin offered unlimited nested notebooks.
It changed my entire outlook on organizing my content. Gone were the days of trying to balance an unruly long list of notebooks vs cramming hundreds of notes in as few categories as possible.
So to me it was hidden until Joplin opened my eyes
I added a disclaimer to my OP saying that I'm interested in a broad definition of "hidden." In no way, though, should this be seen as knocking the hard work you and others have done on the documentation. Or even with Joplin itself. I think even if someone were to read the documentation start to finish when they began using the software, even features in the docs could end up "hidden" for some users. And of course there could be features added that users didn't catch. And some may be "hidden in plain sight."
I really like the folder-nesting-in-subfolders feature. It makes arranging groups of tasks easy. It seems limitless, though I think I've only been twelve levels deep at the most. The only drawback is that it has limited use when I synch up to my Android phone.
The above content is based on the data api implementation, without it, I may not be able to stick to joplin for so long
If you want to play by yourself, you can refer to the official document of joplin. In addition, if you like TypeScript/JavaScript, the joplin-api package above should be out of the box Ready to use, support nodejs, browser runtime.
Maybe not a hidden feature of Joplin itself, but in combination with the windows os, I can quickly download and add PDF files to a note from the net as long as the web clipper cannot clip them:
The browser has the pdf open in a tab
Joplin note is open in the markdown editor (because that is what I use)
Place the cursor where I want the PDF to be inserted and click "attach file"
Copy and paste the URL from the browser URL field to the "file name" field of the "Open" dialog and press OK
Also works with "shift-right-click, copy as path" from the windows explorer in case I found something I would like to put physically into a Joplin note to have it synced accross my devices.