What is the purpose of a dot before an additional CSS property?

Question

This is what I have in the code:

min-height: 35px;
.min-height: 25px;
}

What does the second line do? I assume it serves cross browser styling purposes but not sure which one for.

Answer 1

My guess would be it is targetting IE 6 and 7, though usually _ or - were used instead.

Due to a parsing error, Internet Explorer 6 and below wouldn't fail on properties that were prefixed with non-alphanumeric characters.

and

Although Internet Explorer 7 corrected its behavior when a property name is prefixed with an underscore or a hyphen, other non-alphanumeric character prefixes are treated as they were in IE6. Therefore, if you add a non-alphanumeric character such as an asterisk (*) immediately before a property name, the property will be applied in IE and not in other browsers.

http://www.webdevout.net/css-hacks#unrecommended-vendor_prefix