When you are simply copying a number, you are however, not copying a database or compilation. In this sense you don't even rise to the level of unfair-use as in the case you cited of Rural Telephone. There, they stated not that they had the right to *each* name, but rather that the amount of copying (the entire list) constituted unfair use.
If the case had merely been about copying a name, it never would have made it past the lowest court.
As regards this particular case, there is precedent that purely mechanically-created numbers can not be copyright. As in the case where Thomas West erroneously claims a copyright to the page numbers of their edition. Patently silly on its face, page numbering shows no creativity.
The bar set by the Supreme Court is that the copyright claim must stand on some level of creativity. Regardless of that, copying simply segments of text falls under fair-use. The CAS would have to create the ridiculous position that the number itself and each number individually, constitute an entire work and that that work is original and creative advancing some art, therefore copying it would be unfair as you'd be copying the entire work.
I doubt we have anything to worry about in using their numbers in our work.
Will Johnson
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