WordPress/wp-includes/blocks/classic/block.json

{
	"apiVersion": 2,
	"name": "core/freeform",
	"category": "text",
	"attributes": {
		"content": {
			"type": "string",
			"source": "html"
		}
	},
	"supports": {
		"className": false,
		"customClassName": false,
		"reusable": false
	}
}