Using HTML in email and on website text fields

Question

If I want to use HTML to manipulate the text on a forum or insert images in the description of an ebay listing or for any number of reasons a person could find to use HTML in a text field online.. do you have to use the full HTML structure? Or do you simply just insert the tags you need?

Answer 1

html tags must be there, the rest is not really needed.

As example meta tags can help you to resize the html page for different devices, without them your page will look ugly, you don't must use them, but it is better to.