Complex sentence: This enforces a "write-once" policy since no other data block can be found with the same address: the addresses of multiple writes of the same data are identical, so duplicate data is easily identified and the data block is stored only once.
Split into simpler sentences: This enforces a write-once policy since no other data block can be found with the same address. The addresses of multiple writes of the same data are identical, so duplicate data is easily identified and the data block is stored only once.