There is already a question about the significance of the swastika and Pandya's answer describes it in detail, but one part of it says :
Note: only right Swastika is almost used and reverse (left) Swastika is believed inauspicious sometimes.
I have also heard this too. Right swastika is this:
And this is the left swastika/mirrored image swastika:
Is there any indication in scripture itself that what we call the mirrored image swastika is inauspicious or forbidden?