Plus, Obsidian kind of already has this functionality. You can give any note an alias, and all linking to that alias will instead link to the note. So if you're not worried about being agnostic, and unless if you want to mark every single note, I still don't see the point. And even then, even assuming that you do want every note with a code alias, you can just set it up on a template.

(developer here)

I specifically tried to make this mostly Obsidian-agnostic - the algorithm to generate these note codes is very simple and only requires the note's path relative to the vault.

Here's the whole algorithm in Python:

    import hashlib
    
    def hash_string(s):
        h = hashlib.sha256(s.encode()).digest()
        n = ((h[0] << 16) | (h[1] << 8) | h[2]) % (32**4)
        a = '0123456789ABCDEFGHJKMNPQRSTVWXYZ'
        r = ''.join(a[n // 32**(3-i) % 32] for i in range(4))
        return f"{r[:2]}-{r[2:]}"

Sounds like the same could be done with a slightly longer, but far more readable date + sequential identifier. Such as `YY-xxx` or `YYMM-xxx`.

This looks fine, but then if I rename the note, the code changes, invalidating all the hand-written notes links. So it feels unpractical. I would still prefer to encode the creation timestamp and put it in the title/filename/property. At least this would be fixed.

Plus, the existing linking system allows you to link to a particular heading within an existing note.

From memory… you begin with typing [[ to start the incremental autocomplete on note filename, then when the desired one is top of the list, press # to select a section based on heading.