Vanilla or modded DayZ servers
Players say vanilla when they mean the base game: no traders, no extra guns, no map mod. The directory cannot see house rules. It can see a modded flag, and sometimes it can see the workshop list. Those are the only two facts this site will claim. Everything else is the server name, which is advertising written by the owner.
What vanilla means here
The vanilla list is every online server the crawl has not marked modded. That includes official Chernarus, official Livonia, and community servers that really do run the base game. It can also include a server whose flag was never set. Open the dossier. If workshop mods are listed, the server is not vanilla in the way you meant, whatever the flag says. If the list is empty and the flag is clear, you are as close as this directory can get.
What modded means here
The modded list is the opposite flag. A four-mod quality-of-life server and a Namalsk server both land here. The map column separates them. The dossier separates them further: file id, workshop name, and a link to the Steam page. The launcher downloads from those ids at connect time. You should still look, because a single mod can change loot, stamina, or the entire map.
Flags the list does not have
There is no reliable "no traders" filter and no "boosted loot" filter. Owners put those words in the hostname. Search the browser by name when you care, and treat the hit as a claim. First person and third person are real fields on the server, and the dossier shows them, but the list endpoint cannot filter the whole population by perspective. A page that pretended to would only be filtering whatever happened to be on screen.
Official is a third question
Vanilla is not the same word as official. Official is the public hive. A community server can be unmodded and still not be official, which means your public-hive character does not join you. If you want both constraints, start on official and skip anything whose dossier lists mods. If you want a private unmodded server, start on community and then vanilla, or open dossiers until the mod list is empty.
Modded servers cost time on the first connect and disk space after that. Vanilla servers cost you the toys. Neither is safer. A vanilla Chernarus server with a hundred people is usually more violent than a quiet modded server with a dozen. Read the player count. The flag only tells you about the workshop.
What to read on the dossier
The workshop list is a column of names and file ids. A name you do not recognize is a reason to open the Steam page before you connect, not a reason to assume it is cosmetic. Map mods are obvious because the map column already changed. The dangerous ones are the small lists: a stamina mod, a loot mod, a trader, a gun pack that makes the coast irrelevant. If the list is long, budget the download. If the list is empty on a server marked modded, the crawl missed the names and the launcher will still try to fetch them when you connect. Wait for that instead of assuming the flag was a mistake.
Owners describe their servers in the hostname because that is the only billboard the game gives them. Wipe dates, loot rates, and "no KOS" rules live there. This directory repeats the name and does not grade it. Search is there when you want those words. The vanilla and modded pages exist so you do not have to trust a word in the name to throw away half the list. Use the flag to get close, then use the dossier to see what the server actually sent to the query.