NOTE: The paradelle is one of the more demanding French fixed forms, first appearing in the langue d’oc love poetry of the eleventh century. It is a poem of four six-line stanzas in which the first and second lines, as well as the third and fourth lines of the first three stanzas, must be identical. The fifth and sixth lines, which traditionally resolve these stanzas, must use all the words from the preceding lines and only those words. Similarly, the final stanza must use every word from all the preceding stanzas and only those words.
For more on Collins’ joke of the paradelle see its Wikipedia entry: http://en.wikipedia.org/wiki/Paradelle