Re: Newbie questions

It may be desirable to label units even when their quantity is zero (0), but it is not required.

It may makes clear your intentions to others who may read your code. 

For example:

#someDiv { 

border-width: 0;

}

If I decide to have a border, does the author suggest I it change with the size of my text (em), or should it be a fixed with (px, cm..etc..) ? 

If I write it like this:

#someDiv {

border-width:0em;

}

This makes it clear that if there is a border, I intend for the border should be variable in size.