I am always interested in the ways of scoring the sound of the poem, especially a poem with long lines. Spaces within a line, double colons, slashes, are indications of pause, of breath, of urgency, they are not metrically exact as in a musical notation but they serve (I hope) to make the reader think about the sound of the poem - just as traffic symbols, when driving, make us almost unconsciously aware of a steep hill, an intersection, an icy bridge etc.