BGCODE block rundown for restarting prints?  

BGCODE block rundown for restarting prints?

It has happened to us all, a print fails in the middle and you have a fair idea of where/what went and you want to clear the errors and restart the print when it failed. This is especially true on the XL where a long-running complex print is a challenge to start over. I ran into it about 12 hours into a 36 hour print using specialty filament. Where there were no issues with the print, simply had a hardware issue that needed to be resolved. Once resolved, I needed to reset z and continue. 

Is there a rundown on commands to leave in and edit out when restarting from a failure? For instance I don't want to recalibrate the bed if the current print is still in place. I might have to reset the Z level if I did not catch the failure for a period of time.

I can 'easily' find the spot in the g-code to restart at, but want to make sure the machine is in the proper state rather than crashing it. Things like heaters on, extruder heated, Z-level correct etc.