I have been working on a project and I have a question about meta tags.
One of the tags I use for title of a content.
<meta name = "subject" content = "post-title">
I was looking for more tags than I use for adding between < head > < /head >. I found out Facebook, Twitter and so on has their own tags. So, my question is
What happened if I use each other between < head > < /head >? Is there anything wrong?
<meta name = "subject" content = "post-title">
<meta property = "og:title" content="post-title" />
<meta name = "twitter:title" content="post-title">
As you know search engines care about the meta tags. Does Google send me to sandbox if I use these three similar meta tags?
HTML5 doesn’t restrict how many meta elements you may have.
We can never know for sure what specific consumers (like search engines) would like to see or how they handle it (and discussing this is off-topic on Stack Overflow), but there is no reason to assume that they’d have a problem with this.
In HTML5 you may only use metadata names that are defined or registered.
You’ll see that subject is not a valid metadata name.
In your specific example, you could omit one meta element, as you are using RDFa for og:title, and you can have a metadata name (in name) and an RDFa property (in property) on the same meta element:
<meta name="twitter:title" property="og:title" content="post-title">