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

{
    "jcr:primaryType": "nt:unstructured",
    "jcr:mixinTypes": [ "mix:language" ],
    "jcr:language": "cs",
    "results-plural": {
        "jcr:primaryType": "sling:MessageEntry",
        "sling:key": "{0,plural,one{# result} other{# results}}",
        "sling:message": "{0,plural,one{# výsledek} few{# výsledky} other{# výsledků}}"
    }
}