What does "Anti-Limestone" mean?

[Iculus]

I've seen the term "anti-limestone" used a lot lately to describe a specific showerhead, does anyone know what this means?

 

[Chris]

Anti usually mean No! or Against! where I am from and Limestone is a Rock so I am guessing it means No Rocks! or Against rock!

Really it is likely a marketing gimmick to make you think that that particular shower head will not build up Calcium or lime from Hard water. I hardly think it would work and if it did probably not for very long.