Alright so I'm not proud of what I'm gonna ask but anyways.

I know almost all the notation (clearly not all) and here I am confused.

9\11 is obviously a slide from 9 to 11, but what is


Where it doesn't slide to a particular fret?
it doesnt slide to any particular fret. just slide it. and depending on which way the slash is going, thats the way you slide it. so for '9\' you would slide from 9 to anywhere around the eleventh fret or something around there.