My system shouldn’t restrict where you keep things or what tools or sites you use. But this is where an index is critical, and this demonstrates why really nicely.
First, the solution. And this is the endorsed-by-JD, will-be-supported-by-software format. Do this:
10-19 Area whatever
11 Category you-know-what
11.01 My item in one place
- Location: Pinterest[1]
11.02 My item in another place
- Location: Google Drive
11.03 One more item
- Location: MacBook/~
[1]: And you’ll be able to [markdown](URL here) format links here so that they become clickable.
You could also leave yourself a note against any item.
11.04 My item
- Note: Whatever I want to remember.
Basically after any item you can enter - [Key]: [Value]
and that’ll be valid.