Correct Breadcrumbs Structure with child - schema

Question

Which one is correct breadcrumb structure?
Example 1:
<a href="http://example.com/topic" itemprop="url">
<span itemprop="title">Topic Archive</span></a>
<div itemprop="child" itemscope itemtype="http://data-vocabulary.org/Breadcrumb" style="display: inline;">
<a href="http://example.com/topic/parent-category" itemprop="url">
<span itemprop="title">ParentCategory</span></a>
</div>
<div itemprop="child" itemscope itemtype="http://data-vocabulary.org/Breadcrumb" style="display: inline;">
<a href="http://example.com/child-category" itemprop="url">
<span itemprop="title">Child Category</span></a>
</div>
<span>Post Title Goes Here</span>
</div>
Example 2:
<div id="breadcrumb">
<span itemscope itemtype="http://data-vocabulary.org/Breadcrumb">
<a rel="home" href="http://www.example.com/topic" itemprop="url"><span itemprop="title">Topic Archive</span></a> ›
<span itemprop="child" itemscope itemtype="http://data-vocabulary.org/Breadcrumb">
<span itemprop="title">Parent Category</span> ›
<span itemprop="child" itemscope itemtype="http://data-vocabulary.org/Breadcrumb">
<span itemprop="title">Child Category</span> ›
</span>
<span>Post Title Goes Here</span>
</span>
</span>
</div>
Example 3:
<div id="breadcrumb">
<span itemscope itemtype="http://data-vocabulary.org/Breadcrumb">
<a rel="home" href="http://www.example.com/topic" itemprop="url"><span itemprop="title">Topic Archive</span></a> ›
<span itemprop="child" itemscope itemtype="http://data-vocabulary.org/Breadcrumb">
<span itemprop="title">Parent Category</span> ›
<span itemprop="child" itemscope itemtype="http://data-vocabulary.org/Breadcrumb">
<span itemprop="title">Child Category</span> ›
<h1 itemprop="child" itemscope itemtype="http://data-vocabulary.org/Breadcrumb">
<span itemprop="title">Current Post Title</span> ›
</h1>
</span>
</span>
</span>
</div>
Test the code here: Google Testing Tool
For example number 3, is it right to include the current page in breadcrumb schema? Do I violate any rules?

Answer 1

If you want to use data-vocabulary.org (which is already considered outdated), example 3 is the most correct. It is standard to include the current page in the breadcrumb. Example 1 is not correct since you have not nested your elements. In this case, you would want to add the itemref property and give ids to your divs. The itemref property should equal the id of the next child. https://developers.google.com/structured-data/breadcrumbs?rd=1
You should definitely consider moving to schema.org, since that is the format the major search engines will almost certainly agree upon. According to schema.org, none of these are the proper implementation. Your overall list should be marked as a BreadcrumbList, with each item being marked as a ListItem. Yes, by convention, the current page is the last item in the list.
https://schema.org/BreadcrumbList