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

{
	"apiVersion": 2,
	"name": "core/verse",
	"category": "text",
	"attributes": {
		"content": {
			"type": "string",
			"source": "html",
			"selector": "pre",
			"default": "",
			"__unstablePreserveWhiteSpace": true
		},
		"textAlign": {
			"type": "string"
		}
	},
	"supports": {
		"anchor": true,
		"__experimentalFontFamily": true,
		"fontSize": true
	},
	"style": "wp-block-verse",
	"editorStyle": "wp-block-verse-editor"
}