{% if entity.reference_systems %}
    <h2>{{ _("external reference systems")|uc_first }}</h2>
    {% for link in entity.reference_systems %}
        {% set system = g.reference_systems[link.domain.id] %}
        {% if system.resolver_url %}
            <a href="{{ system.resolver_url + link.description }}" target="_blank" rel="noopener noreferrer">
                {{ link.description }}
            </a>
        {% else %}
            {{ link.description }}
        {% endif %}
        ({{ g.nodes[link.type.id].name }} {{ _('at') }} {{ link.domain|link|safe }})
        <br>
    {% endfor %}
{% endif %}