To qualify as an outlying municipality, the municipality must have at least 1.5% of its resident population aged 15 and above commuting to school or work into one of the central cities. To qualify as a central city, a city must either be a designated city of any population or a non-designated city with a city proper population of at least 500,000.
To qualify as an outlying municipality, a locality must have at least 1.5% of its resident population aged 15 and above commuting to school or work into one of the central urban centers. To qualify as a central city, a metropolis must either be a designated urban center of any size or a non-designated urban center with a municipal population of at least 500,000.