When a proxy list marks an entry 'elite' or 'high anonymity,' it's describing the strongest privacy tier a proxy can offer.
What makes it elite
An elite proxy hides your real IP and also strips or avoids sending the headers that would reveal a proxy is being used in the first place, like X-Forwarded-For or Via. To the destination server, the traffic looks like an ordinary direct visitor.
Why they're scarce on free lists
Maintaining a proxy that never leaks identifying headers takes more careful server configuration than a basic open proxy, and elite proxies tend to attract heavier use once discovered, which shortens their useful lifespan on public lists.
Verifying the claim
Anonymity labels on public lists are self-reported by the scraping tool that built the list and can be wrong or outdated. Running a proxy through a checker before trusting the 'elite' tag is worth the extra minute.