A css rule that I have never seen.

[grabenair]

Can someone please tell me what this css rule does?

 

clip:rect(20px, auto, auto, 20px);

 

I found it in a wordpress theme that I am modifying.

[newseed]

See clip: rect

 

It's rarely used but for this theme, its more than likely used for users that don't have a clue about sizing images to fit a particular area. Ideal for a fixed width/heigth div for images of different dimensions without skewing them.