Linked from
The 11 pages that link to Punctuation, each with the reason it gives.
OrthographyRelated: Punctuation conventions form part of orthography beyond the spelling of words.
EnjambmentRelated: Punctuation can reinforce a line ending or complicate its apparent pause.
E. E. CummingsRelated: He varies punctuation to interrupt, compress, or redirect a poem’s movement.
EmoticonRelated: These marks supply the eyes and mouth in familiar text-based faces.