# Advanced usage

- [Authorization](/advanced-usage/authorization.md)
- [User content state](/advanced-usage/user-content-state.md)
- [Multiple user states per object](/advanced-usage/context-ids.md)
- [Impersonating users](/advanced-usage/impersonation.md)
- [Basic completion tracking](/advanced-usage/completion-tracking.md)
- [Localization](/advanced-usage/localization.md)
- [Cluster](/advanced-usage/cluster.md)
- [Addons](/advanced-usage/addons.md)
- [Customization](/advanced-usage/customization.md)
- [Performance optimizations](/advanced-usage/performance-optimizations.md)
- [Privacy](/advanced-usage/privacy.md)
- [Forward proxy support](/advanced-usage/proxy.md)
- [Security](/advanced-usage/security.md)