Another TAB question

I picked up a songbook for Foo Fighters recently and encounter a TAB notation I don't understand and which they do not explain.

----------------------------
-----------------------6----
---6---6---------------6----
---6---6---x--x--x--x--6----
---6---6---x--x--x--x--4----
---4---4---x--x--x--x-------

What do the X's mean??? I am accustomed to them meaning that a string should not be played...but if there are no open strings marked to be played, and just X's, it doesn't make sense to me.

Anyone have any explaination?

Thanks

Dave

that last line of 6's should be alinged over each other. Too bad you can't edit your own posts :( (can you?)

Could they just be so called "rests" as they have in normal musical notation. So you just wait four beats, before you play that last cord, in this measure.

it means you have to mute the strings so you're holding the 4666 chord and then you raise your fingers so they are still laying on the strings but not pressing the notes and then you strum four times , it are no rests.

if you don't understand it just ask!