OCTET • FREE TRANSLATOR.ORG • Definition of Octet

... consists of thirteen lines in iambic tetrameter and two lines of two iambics each; in all, one line more than the sonnet's count. There are two rhymes only, since the short lines must be considered blank, and are, in fact, identical. But it is a difficult mode. It is true, he allowed, that the octet of the sonnet has only two rhymes, but these recur only four times, and the liberty of the sestet tempers its despotism,—which I thought a pretty phrase. He pointed out the dangers inherent in a restricted rhyme, and cited the case of Browning, the great rhymster, who was prone to resort ...

— In Flanders Fields and Other Poems - With an Essay in Character, by Sir Andrew Macphail • John McCrae