An empty label composed nothing, so a module served at the bare domain (a node's own site) had to keep a full name — the one route the label model could not express. The zone-file convention '@' now composes to the public domain itself, no leading dot, so the apex is a label like any other. Test added. Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF