What is the use of this option?

What’s the use of this IX style option?

Hi! Thanks for pointing that out–that’s actually a bug that the checkbox is there. This checkbox used to exist back when the format painter was available, but should be removed from the dialog in Axure RP 9. I’ve gone ahead and filed a bug report for this, and we’ll update this thread when there’s a fix. In the meantime you can turn on “Check for Updates” in Axure RP or keep an eye on the RP 9 beta release notes page for news on released bug fixes. Thanks!