src/main/resources/SLING-INF/apps/sightly/locales/de_finance_basename.json

{
    "jcr:primaryType": "nt:unstructured",
    "jcr:mixinTypes" : [
        "mix:language"
    ],
    "jcr:language"   : "de",
    "sling:basename" : [
        "finance"
    ],
    "bank"          : {
        "jcr:primaryType": "sling:MessageEntry",
        "sling:key"      : "the bank",
        "sling:message"  : "die Bank"
    }
}