I am able to use <big> tag in HTML5 document, why?

Question

As listed on various websites <big> tag is not supported by HTML5 but I am still able to use it. Can anyone explain me why ?

Answer 1

Try it yourself in any HTML5 document

Answer 2

Yes it executed the <big> tag being a HTML5 document

Answer 3

Bro I don't have any problem, it's good , but many(almost every) websites says <big> tag is not supported by HTML5, but in practical it is supporting. Why?is there any bug ?