pub const CAA_RECORD_PATTERN: &str = r#"^(0|128)\s([a-zA-Z0-9]+)\s(".+")$"#;Expand description
Regex for a Route53 CAA record value: a flag 0 or 128, a tag, and a quoted value, each
separated by a single whitespace. The single \s (not \s+) matches the service’s own
single-separator requirement.