1.9 Upgrade Guide: examples show correct usage but intro text says both

[rdworth]

In the .attr() versus .prop() section there's a sentence that introduces some code samples "Here are some examples of correct and incorrect usage when setting checked on a checkbox;" but it's a bit confusing because then all four examples are correct usage

// Correct if changing the attribute is desired
$(elem).attr("checked", "checked");
// Correct for checking the checkbox
$(elem).prop("checked", true);

// Correct if removing the attribute is desired
$(elem).removeAttr("checked");
// Correct for clearing the checkbox
$(elem).prop("checked", false);

where the sentence said there were correct and incorrect usage examples coming.