Enclosed rhyme

Enclosed rhyme (or enclosing rhyme) is the rhyme scheme ABBA (that is, where the first and fourth lines, and the second and third lines rhyme). Enclosed-rhyme quatrains are used in introverted quatrains, as in the first two stanzas of Petrarchan sonnets.

Example

How soon hath Time, the subtle thief of youth,		A
Stolen on his wing my three and twentieth year!		B
My hasting days fly on with full career		B
But my late spring no bud or blossom shew'th.		A

(From John Milton: "Sonnet VII")^[1]

"Exposure", by Wilfred Owen,^[2] also has an example of enclosed rhyme. Each of the eight stanzas have the ABBA half rhyming sequence:

Our brains ache in the merciless iced east winds that knive us ...		A
Wearied we keep awake because the night is silent ...		B
Low, drooping flares confuse our memories of the salient ...		B
Worried by silence, sentries whisper, curious, nervous,		A
But nothing happens.