"the words 'according to' mean what they say,"
The words "according to" comes from the Greek word "kata".
Tricky word.
ONE English translation won't really give you the essence.
It's the same tricky word in Paul's "kata sarka",
meaning "according to the flesh",
or maybe "in a worldly manner"
or maybe "in an earthly style"
or maybe "physically".
Scholars still argue about this phrase.
You could just about translate the Greek title
"EUAGELLION KATA MARKON" (pardon my mangled transliteration)
as
"The Gospel in the style of Mark"
Iasion