I donít know where you stumble upon such code frequently as Iíve barely seen these rules being used anywhere. And you know, I just put some of them into a search engine of my choice and guess what kinds of results I got? Yes, ANSWERS! You wouldnít believe it!
In a nutshell: All CSS properties with the -moz prefix are non-standard, proprietary properties that only browsers using the Mozilla rendering engine understand and parse. They are ignored by all other browsers and will generate errors in any CSS validator that validate against the common standards set by the W3C. Some of them will become standards with the release of CSS3, and some wonítÖ
Explanatios on their functions can be found in the Mozilla Developer Center
, among other sites.