HTML <center> tag (Not Supported in HTML5)
The HTML <center> is a block level element which contains both block level and inline contents within it. The content written between the <center> elements will be displayed at the middle of the page.
The <center> tag has been deprecated in HTML 4 and obsolete in HTML5.
NOTE: The <center> tag is deprecated now so instead of that you can use CSS property text-align: center; to achieve the same result.
Following are some specifications about the <center> tag
Using <center> tagTest it Now
Using CSSTest it Now
HTML <center> tag does not contain any specific attribute in HTML but it supports the Global Attribute (till <center> tag is not removed completely).