Right, anything after the # is not sent to the server, like other anchors.

tim333 · on March 12, 2021

I wonder how they know which message. I guess javascript on the client reads the stuff after # and sends something derived from it to the server?

selykg · on March 12, 2021

So I created a test Send:

So, it looks like it's pretty simple.

After the # you have two separate things, separated by /

One is an identifier, the other is likely an encoded key (that may or may not depend on a separate password, if specified).

Just a guess, I assume this is documented somewhere