According

King James Dictionary

Accord'Ing, ppr.

1. Agreeing harmonizing.

Th' according music of a well mixt state.

2. Suitable agreeable in accordance with.

In these senses, the word agrees with or refers to a sentence.

Our zeal should be according to knowledge.

Noble is the fame that is built on candor and ingenuity, according to those beautiful lines of Sir John Denham.

Here the whole preceding parts of the sentence are to accord, agree with, correspond with, or be suitable to, what follows. According, here, has its true participial sense, agreeing, and is always followed by to. It is never a preposition.

Webster's Dictionary

(1): (p. a.) Agreeing; in agreement or harmony; harmonious.

(2): (p. pr. & vb. n.) of Accord

(3): (adv.) Accordingly; correspondingly.