The content of the attributes of a meta
tag is by definition just text: no tags are recognized (though character references are parsed). So the example is valid, but this is just a formality. All the rest depends on software that interprets meta
tags. It would however be odd to treat its attributes as anything but plain text.
(AND I THINK SHOUTING IS QUITE SUFFICIENT FOR MAKING THE TEXT LOOK FOOLISH, YOU DO NOT NEED TO BOLD IT.)