ěščřžýáíé to non diacritics (this is NOT complete list, only some)
'ř'=>'r'
'Ř'=>'r'
'ě'=>'e'
'Ě'=>'e'
'á'=>'a'
'é'=>'e'
'í'=>'i'
'Ó'=>'o'
'ó'=>'o'
'Ú'=>'u'
'ú'=>'u'
'ů'=>'u'
'ý'=>'y'
'Č'=>'c'
'č'=>'c'
'ď'=>'d'
'ť'=>'t'
'ĺ'=>'i'
'ň'=>'n'
'Š'=>'s'
'š'=>'s'
'Ž'=>'z'
'ž'=>'z'