The "!" character is used by the debugger to specify a breakpoint.
You can put it in code as well.
+ Code Snippetmake object cube 1,1
do
!rotate object 1,0,object angle y(1)+1,object angle z(1)+1
loop
You can also do it in the ide with ctrl+shift+f2 or right click > toggle breakpoint.
When you run it in step through mode the ide prefixes every line with a "!".
Not really much use as the debbugger crashes too much to make it useable. It crashed in that bit of code.