[PS1.6 Rich Snippets Google SEO] Microdata. More information: https://developers.google.com/search/docs/advanced/structured-data/product#microdata #PS16 #SEO

product.tpl

1. Only 1 tag of product shoulb be exist.

<p class="our_price_display" itemprop="offers" itemscope itemtype="https://schema.org/Offer">

<meta itemprop="priceValidUntil" content="{'Y'|date}-12-31" />
<meta itemprop="url" content="{$link->getProductLink($product)}">
</p>



<div itemprop="brand" itemscope itemtype="http://schema.org/Brand">
	<meta itemprop="name" content="{$product_manufacturer->name}">
</div>

{if !empty($product->reference) && $product->reference}
	<meta itemprop="mpn" content="{$product->reference}" />  <!-- If not have mpn, use the reference val. -->
{/if}

#######IF THE CODE CAME FROM ANY MODULE THAT NOT HAVE TAGS:
<meta itemprop="availability" content="{$priceDisplay}" />



<!-- Put out of Offer block. -->
<meta itemprop="brand" content="{$product.manufacturer_name}" /> 
<meta itemprop="sku" content="{$product.reference}" />
{if !empty($product.reference) && $product.reference}
	<meta itemprop="mpn" content="{$product.reference}" />
{/if}
<meta itemprop="description" content="{$product.description|strip_tags}" />

FOR PRESTASHOP 1.6.XX
<meta itemprop="brand" content="{$product->manufacturer_name}" />
<meta itemprop="description" content="{$product->description|strip_tags}" />

productcomments.tpl or productcomments-extra.tpl

Warning "ratingValue" when no reviews in product.

Just ommit aggregate Rarting
themes/cellular/modules/productcomments

FOR PRESTASHOP 1.6.XX
Before:
<div id="product_comments_block_extra" class="no-print col-sm-5" itemprop="aggregateRating" itemscope itemtype="https://schema.org/AggregateRating">
After:
<div id="product_comments_block_extra" class="no-print col-sm-5" {if $nbComments != 0} itemprop="aggregateRating" itemscope itemtype="https://schema.org/AggregateRating"{/if}>


Add this one if apply,avoid "One of ratingCount or reviewCount must be provided.":
<meta itemprop="reviewCount" content = "{$nbComments}" />