Doctype language declaration problem

[Silviu]

Hello,
I have a problem with an SEM Rush warning on a website audit, for www.enjoyprepaid.com. It tells me "5852 pages are lacking language declaration", but I don't understand what it means and how to actually fix this problem. Also I run a W3 validator and have a doctype and language problem but again don't understand what they mean and how to fix them https://validator.w3.org/nu/?doc=http%3A%2F%2Fwww.enjoyprepaid.com%2FAfghanistan-calling-cards-2.html

[Mobilio]

Yes - iso-8859-15 is very outdated encoding. Validator suggest that you should use UTF-8.I believe that this is also SEMRush issue too.

Fix just wrote this:

and bug will be fixed.