Vue Guideline: Performance — Use v-once for static content. Description: Skip re-renders for static elements. Do: v-once on never-changing content. Don't: v-once on dynamic content. Good Example: <div v-once>{{ staticText }}</div>. Bad Example: <div v-once>{{ dynamicText }}</div>. Severity: Low. Docs: https://vuejs.org/api/built-in-directives.html#v-once.