Override DOCTYPE

Hi,

I want to override this header in my Plone (4.3.6) site:

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="pt-br" lang="pt-br">

to

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml" lang="pt-br">

The reason is: when i try to validate this site: https://www.mostardas.rs.leg.br/ with this tool http://www.acessibilidade.gov.pt/accessmonitor/, I'm getting this error:

"The document type does not allow the use of the attribute xml:lang

HTML sólo ofrece el uso del atributo lang, XHTML 1.1 sólo permite xml:lang, mientras que XHTML 1.0 (como medida de transición) permite ambos atributos. XHTML servido como text/html utiliza los atributos lang y xml:lang del elemento html."

How can I do this?

Thanks,
Rafahela

If you are using Diazo you can set the doctype in the manifest.cfg file: https://docs.plone.org/external/plone.app.theming/docs/index.html#the-manifest-file.

Ok, I did this.

And the html tag?

Thanks,
Rafahela