"Ska Strumming"

Im learning Catch 22's "12341234" and it has this weird strum/mute/strum/mute thing, or so it sounds like it, and its really fast which makes me think that its not struming then muteing it after. The tab says to use "Ska Strumming" Wtf is that?? Anyone know what im tlaking about, and how to do it?

ska strumming is kindof a technique, kindof a rythym, and kindof just an emotion when strumming the strings. usually ska strumming is on the upbeat, keeping a faster pace than reggae. it takes a little practice to get it good, i started and hardley knew what the **** i was doing, i used to be way into ska punk and stuff, so thats the first stuff i learned. with practice your strums will sound just like catch 22. saw them at a local venue, BTW. they kicked major ass.

Yeah, I figured, But how do you do it? It sounds punctuated on the records, which makes me think its strummed then muted soon after.

yeah you just have to play the upstroke and mute the downstroke. start out slow and just keep getting faster and faster