Complex sentence: Since the 1990s, there has been a convergence in approaches toward architecture description, with IEEE 1471 in 2000 codifying best practices: supporting, but not requiring, multiple viewpoints in an AD.
Split into simpler sentences: Since the 1990s, there has been a convergence in approaches toward architecture description, with IEEE 1471 in 2000 codifying best practices. Supporting, but not requiring, multiple viewpoints in an AD.