8.191 Titles of Poems. Quoted titles of most poems are set in roman type and enclosed by parentheses. A very long poetic work, especially one constituting a book, is italicised and not enclosed in quotation marks.
Robert Frost’s poem “The Housekeeper” in his collection A Boy’s Will.
In literary studies where many poems, short and long, are mentioned it is usually better to set all their titles in italics.
8.192 First lines. Poems referred to by first line rather than by title are capitalized sentence style (but according to the capitalization used in the poem itself). See also 18.149.
“Shall I compare thee to a Summer’s day?”
8,193 Titles of plays. Quoted titles of plays, regardless of the length of the play are italicised.
Shaw’s Arms and the Man, in volume 2 of his Plays: Pleasant and Unpleasant
8.194 Divisions of plays or poems. Words denoting parts of long poems or acts and scenes of plays are usually lowercased, neither italicised nor enclosed quotation marks.
canto 2 stanza 5 act 3, scene 2