Using a back-tick quoted thing sends thing to the os to be executed. Not sure how useful that would be right now, but I could see where it might come in handy at some point.

jrnl notes "@jrnl Trying back-tick to enter date into entry.  I'm going to try to use the back-tick to enter the date here [`date`] with the **date** command."

It should put the date into the entry here "date here []" and it does do that. See entry below:

[2020-04-16 14:58] @jrnl Trying back-tick to enter date into entry. I'm going to try to use the back-tick to enter the date here [Thu Apr 16 14:58:31 EDT 2020] with the date command.

So, it could be useful. Will have to think how I could use it.