%-6.2d, what does the .2 mean

Alright, so I've searched the book I'm learning from, as well as the internet, and can't seem to find an answer to this...so I am turning to /prog/ as my last resort:
in the conversion specification %-6.2g, what does the .2 mean?
I know that the -6 means that there are a maximum of 6 characters shown, and that it is left justified, but the book doesn't mention what the number following a decimal means.
Help is greatly appreciated, thanks in advance

# of decimal places.