hugo/tpl/tplimpl/embedded/templates/schema.html

<meta itemprop="name" content="{{ .Title }}">
<meta itemprop="description" content="{{ with .Description }}{{ . }}{{ else }}{{if .IsPage}}{{ .Summary }}{{ else }}{{ with .Site.Params.description }}{{ . }}{{ end }}{{ end }}{{ end }}">

{{if .IsPage}}{{ $ISO8601 := "2006-01-02T15:04:05-07:00" }}{{ if not .PublishDate.IsZero }}
<meta itemprop="datePublished" content="{{ .PublishDate.Format $ISO8601 | safeHTML }}" />{{ end }}
{{ if not .Lastmod.IsZero }}<meta itemprop="dateModified" content="{{ .Lastmod.Format $ISO8601 | safeHTML }}" />{{ end }}
<meta itemprop="wordCount" content="{{ .WordCount }}">
{{ with .Params.images }}{{ range first 6 . }}
  <meta itemprop="image" content="{{ . | absURL }}">
{{ end }}{{ end }}

<!-- Output all taxonomies as schema.org keywords -->
<meta itemprop="keywords" content="{{ if .IsPage}}{{ range $index, $tag := .Params.tags }}{{ $tag }},{{ end }}{{ else }}{{ range $plural, $terms := .Site.Taxonomies }}{{ range $term, $val := $terms }}{{ printf "%s," $term }}{{ end }}{{ end }}{{ end }}" />
{{ end }}