SeeMeCNC Rostock MAX v2 Assembly Manual page 263

You can see an example of this below – it's currently showing layer 6 of the Ignite key fob that
I've been using as my example part.
The Help mode (accessed by clicking the "Help" tab next to "Visualization") is a very handy
feature when you'd like to see what all that noise in the G-Code Editor is actually doing.
When you click on a G or M code that Repetier-Host knows about, it'll pull a description out of
its database and display the information in the Help window as shown above.
If Repetier-Host doesn't know what a G or M code is, it won't display anything in the Help
window at all.
Rostock MAX v2 Assembly Guide
263