Blogspot - List of Keywords

* data:blog.pageType

Type of the page, pasible value are. [index, item]
Some Usage like creating condition:
<b:if cond='data:blog.pageType == "index"'>

* data:blog.url

The URL con the current pages

* data:blog.pageName

Page name or the post name
<meta expr:content='data:blog.pageName' property='og:site_name'/>

* data:blog.title

Page Title
Usage:
<meta expr:content='data:blog.title' property='og:title'/>
OR
<title><data:blog.pageTitle/></title>