The forum defendant rule under 28 USC 1441(b)(2) is a procedural, not a substantive bar to removal jurisdiction and so must be raised by a remand motion brought within 30 days of the filing of the removal notice or it is waived. Here, the remand motion was filed on the 31st day after the removal petition. Nevertheless, it was timely because the removal petition was premature, having been filed after the electronic filing of the complaint but before the superior court clerk processed, endorsed, or otherwise acknowledged that the complaint was officially filed. The premature removal notice didn’t start the 30-day clock running on the remand motion. So the district court properly ordered the case remanded under the forum defendant rule.