Moved from @Glenn_McGrew_II's 4.4 post to here
First of all, the slide for this problem, "Selected CSS Property Shorthands", indicates the shorthand is (I'm quoting from the slide): "margin or padding: 0 10px 0 10px / 0 10px 0 / 0 10px;" with explanatory text below: "/*top right bottom left / top right&left bottom / top&bottom right&left */".
In the code, there is a minor error in that the word "or" is the same color as "margin" & "padding", which may cause some people to erroneously believe it's one attribute instead of two. Changing the color would fix that.
The second error is in the font shorthand: "font: 16px/18px bold italic san-serif;" with the explanatory text: "/* size/line-height weight style family */".
There should be commas between the font names, and family but, since it shows only the basic family and no specific font names, that is not obvious.
moderator: no commas in
font shorthand, but there are commas when separating alternatives within a font-family
moderator: slide referenced (shown by default in challenge 4.4's slide panel)