Action Commands in OctoPrint


I'm working on a plugin that receives and sends some action commands and I have a question about the syntax.
In the documentation, the syntax is sometimes:
// action:command (space between "//" and "action:")
ex.: Action Commands & Hooks
and sometimes there's no space.
ex.:Action Command Prompt & Notifications

Reprap & Marlins M118 don't mention a space.

I'm using no space to send printer notifications to OctoPrint like this:
"M118 A1 action:notification Test" which is sent back to OctoPrint as "//action:notification Test"
and it's working perfectly fine for me.

But I have a user reporting that it's not working for him and adding a space fixed the problem.

Which one to use? And does anyone have an idea why I can't reproduce the issue?

more than likely firmware differences between what you have and what they have.

The notification is shown by OctoPrint. The firmware doesn't matter for that. It's sending the same code back to OctoPrint ("//action:notification Test") for both of us, but apparently the notification is not showing up for him.

Have you compared the serial.log s?