Commenting, shorthand css and function calls:

css_general_3.css

/* -- COMMENTING -- */

/* -- 1linecomment -- */ or /* comment */
/* =============================================================================
   sectionname
   ========================================================================== */


/* -- SHORT HAND CSS -- */
/* -- BAD -- */
#identifier {
  margin-left: 20px;
  background-color: transparent;
  background-image: url('image.jpg');
  background-repeat: no-repeat;
  background-position: top right;
  background-attachment: scroll;
}

/* -- GOOD -- */
#identifier {
  margin: 0 0 0 20px; /* -- 1 2 3 OR 4 parameters-- */
  background: transparent url('image.jpg') no-repeat scroll top right;
}

/* -- FUNCTION CALLS -- */
/* -- BAD -- */
#identifier {
  color: rgba(0,0,0,.2);
}

/* -- GOOD -- */
#identifier {
  color: rgba(0, 0, 0, 0.2);
}