[Typo3] first steps in tv

[Bartosz Aninowski]

> CO-ROOT ROOT Select the HTML element on the page which you want to be the
> overall container element for the template. <div> INNER  (ALL)
>  |-El Header field_header sample header <h2>INNER  (ALL)
>  |-EL Bodytext field_bodytext sample body <p>INNER  (ALL)
>  |-EL Image field_image sample image   <img>(ALL)
>  |-EL Link title field_linktitle Link title <a>INNER  (ALL)
>  |-AT Link Url field_linkurl  <a>ATTR:href  a:attr:href

I've changed field_bodytext  into field_whatever and it works
but why?
is this conflict with previoes DS ?