First of all what is ISO Latin character set? You'll find a brief of ISO 8859-1 (Latin-1) Characters List at
Now, you have a string that contains the HTML syntax of those character set. For example, instead of a comma(,) you have , inside your string. Or, you can have * instead of having the asteroid(*)
You can convert the string having those HTML syntax of Latin char set using a simple regular expression. Inside the regular expression I've used the /e modifier, so that I can use $1, $2, etc variable that returned from regex matching of preg_match. Finally I just converted the ascii to char using chr() function of PHP.
Here is the code that will polish your string after removing the HTML syntax for ISO 8859-1
$html_source = 'Only $1,00!! what the f***??';
$html_source = preg_replace('/(\d\d);/e', 'chr(\'$1\')', $html_source);
Thanks for reading the article.