Boost means high amp as in a boost box or a car battery, for regular charging or trickle charging you should be ok, I usually just remove the ground cable just to be safe.
I have a 2001 GTI LE coming in next week , the guy left the lanyard on for a week which of course drained the battery, then he hooked a boost box to it and tried to jump it off, I am not completely sure because I haven't seen the ski yet but chances are better than good that he popped the diode inside the electrical module when he boosted the battery which means he will be buying an MPEM.