CSS style preferences control how Dreamweaver writes the code that defines CSS styles. CSS styles can be written in a shorthand form that some people find easier to work with. Some older versions of browsers, however, do not correctly interpret the shorthand.
When Creating CSS Rules Use Shorthand For lets you select which CSS style attributes Dreamweaver writes in shorthand.
When Editing CSS Rules Use Shorthand controls whether Dreamweaver rewrites existing styles in shorthand.
Select If Original Used Shorthand to make Dreamweaver leave all styles as they are.
Select According to Settings Above to make Dreamweaver rewrite styles in shorthand for the attributes selected in Use Shorthand For.
When Double-Clicking in CSS Panel lets you select the tool you prefer to use in Dreamweaver to edit CSS rules.