Client-side region filter: the rows matchRegion picks. A numeric input is a key
(an exact ags, leading zeros ignored, or a key padded with zeros that a coarser row
carries shorter); otherwise the rows whose whole name equals the input when there are
any, else every row whose name contains it — case-insensitive, in NFC. A blank region
throws RegionalatlasValidationError rather than matching every row.
Client-side region filter: the rows
matchRegionpicks. A numeric input is a key (an exactags, leading zeros ignored, or a key padded with zeros that a coarser row carries shorter); otherwise the rows whose whole name equals the input when there are any, else every row whose name contains it — case-insensitive, in NFC. A blank region throwsRegionalatlasValidationErrorrather than matching every row.