The article talks about a particular behavior in markdown when leading spaces are potentially ambiguous.  However, it seems that there is an error, as the input in one example contains the strings "one" "two" "three" "four", the output is said to contain "one" "two" "two" "two".<p>When writing programming articles showing actual code, it is quite important to get all the details right.  A reader seeing the first non-reproduceable result will lose confidence in the presentation.