Nametags ​

Per-viewer nametag control: set a player's whole tag, or just its prefix, suffix, or color — for everyone, or for one specific viewer. Rank prefixes, disguises, "you are being watched" markers: all one statement each.

event PlayerJoin {
    execute {
        set nametag of event.player to "<red>[ADMIN] ${event.player.name}"
        set nametag prefix of event.player to "&6[VIP] "
        set nametag suffix of event.player to " &7(AFK)"
        set nametag color of event.player to red
    }
}

Statements ​

Without a for clause the change applies to all viewers, including players who join later — the runtime re-sends nametag state on join. With for <viewer> only that viewer sees it; the same player can look different to different people:

command "spy" {
    arguments {
        target: Player
    }
    execute {
        // only the command sender sees the mark
        set nametag suffix of args.target to " <dark_red>☠" for sender
        send "<gray>Marked ${args.target.name} — only you see it." to sender
    }
}

Colors ​

set nametag color takes one of the 16 protocol team colors, written bare (red, gold) or as any String expression. The set is closed — team color is a protocol enum, not RGB — and the compiler checks literals:

e_nt.sw:6:46: error: unknown nametag color 'badcolor'; valid colors: black, dark_blue, dark_green, dark_aqua, dark_red, dark_purple, gold, gray, dark_gray, blue, green, aqua, red, light_purple, yellow, white

Prefix and suffix strings accept the usual formatting — MiniMessage tags (<gold>) and legacy & codes both work.

How it works (and what that implies) ​

Nametags ride the same mechanism the vanilla scoreboard uses: single-member teams, sent per viewer as TeamsPackets (team names are prefixed ZZZZZ + username so they sort last and never collide with real teams). Consequences worth knowing:

• Nothing is stored on the player entity — it's pure view state. Disconnect cleanup and join re-sends are handled by the runtime.
• Changes are cheap (one small packet per affected viewer) — animating a prefix from a scheduler is fine.
• A server-wide team plugin that also manages one-player teams could fight over the same protocol surface; SwoftLang assumes it owns nametags.

For floating text that isn't attached to a player's head, use text displays or holograms.