/em> under <em>which conditions</em>”
(RBAC + conditions). Specifically:</p><ul><li><strong>&ldquo;who”</strong> are the services in the <code>frontend</code> namespace.</li><li><strong>&ldquo;what”</strong> is to call services in <code>backend</code> namespace.</li><li><strong>&ldquo;conditions”</strong> is the <code>visibility</code> label of the destination service having the value <code>external</code>.</li></ul><h3 id=servicemethod-level-isolation-withwithout-primary-identities>Service/method l