[Indesign 2.0.2] Style Sheet

Hi to all,
I have a paragraph wich is assigned a Style Sheet, but at the end of the Sheet's name there is a "+" (if it is as xpress it means that you have modified something like character dimension ecc..)

I'd like to clear all the style for the paragraph, but if i Click on "No Style" and than i assign a new style the "+" character still remain?

How can i do?

Thanks
Teo