GNOME coverage

What of the GNOME System Administration Guide a DeskOS image can carry, page by page. Audited 2026-10-30 against GnomeProfile and the providers, not against the guide's own assumption that any dconf key is a setting.

This page is also the evidence for ADR 0024: a desktop is adopted because it exposes file-based configuration with precedence and a lock layer that a check can read, not because it is popular. The audit is how "GNOME meets that today" is a claim instead of an opinion.

The vocabulary is closed (settings.additionalProperties: false): a key is reachable only when a semantic field lowers to it. There is no raw-dconf escape, by design (ADR 0005, invariant 5), so "GNOME lets you set it" never implies "DeskOS can".

Guide page	Mechanism	Verdict
Setup
Browse GSettings, dconf, profiles, keyfiles	dconf profile and keyfiles	modelled: the lowerer writes distro.d keyfiles and Platforms declare the database
Custom default values	dconf defaults	modelled, with provenance and layering
Lock down specific settings	dconf locks	modelled; Core ships none (invariant 8)
Store settings over NFS	service-db:keyfile/user first line of the profile	gap: field: the platform owns the profile, and no field asks for it
Why not GSettings overrides	vendor overrides	modelled for the first-boot wallpaper only; no general field
User settings
Notifications on a locked screen	notifications show-banners, show-in-lock-screen	modelled since 2026-10-30 (notifications.banners, .onLockScreen)
Privacy defaults	org.gnome.desktop.privacy recent files, temp/trash removal, telemetry, camera, microphone	modelled since 2026-10-30 (privacy.*)
Dim screen when idle	plugins.power idle-dim, idle-brightness, session idle-delay	modelled since 2026-10-29 (session.idle.blankAfter, .dim, .dimBrightness)
Enable the compose key	input-sources xkb-options	modelled (keyboard.xkbOptions: compose:caps, compose:menu, compose:ralt, compose:rctrl)
Disallow online accounts	online-accounts whitelisted-providers	gap: field, or declined: an account is a person's, not the image's
Single-application mode	custom session plus a wrapper Exec	refused: arbitrary shell (invariant 5)
Disable command line	lockdown disable-command-line	modelled
Disable file saving	lockdown disable-save-to-disk	modelled
Disable printing	lockdown disable-printing	modelled
Disable repartitioning	a polkit .policy file for udisks2	gap: decision: a file with security semantics, not a key; a kind here is a new surface
Disable logout and switching	lockdown disable-log-out, disable-user-switching	modelled
Disallow fingerprint login	PAM, fprintd and a reader	outside: hardware and PAM, not image intent
Lock down extensions	shell enabled-extensions, development-tools	modelled since 2026-10-29 (shell.extensions, shell.developmentTools)
Appearance
Choose the fonts, surface by surface	interface font-name, document-font-name, monospace-font-name; wm titlebar-font; the terminal's font-name	modelled since 2026-10-30 (appearance.fonts.interface, .document, .monospace, .titlebar, .terminal)
Zoom text without changing sizes	interface text-scaling-factor	modelled (appearance.fonts.textScaling, 0.5 to 3.0)
Subpixel rendering and hinting	interface font-rendering, font-antialiasing, font-hinting, font-rgba-order, and fontconfig's own file	modelled (appearance.fonts.antialiasing, .hinting, .rgbaOrder, .lcdfilter): the file for every application, the keys for GNOME and X11
Extra fonts (all users)	files under /usr/share/fonts	artifact: a package or a placed file; deskos-gnome ships Noto (Latin, symbols, math, color emoji), Red Hat Text and Display, Overpass, Gelasio, Liberation, DejaVu, Carlito, Caladea and the URW base 35, and deskos-adwaita adds Adwaita Sans and Mono (ADR 0026)
Extra fonts (one user)	$HOME/.local/share/fonts	outside ($HOME)
Extra backgrounds	files plus the wallpaper key	artifact plus the modelled wallpaper key
Lock screen shield	screensaver picture-uri	modelled since 2026-10-29 (appearance.lockShield; the wallpaper is the default)
Lock the screen when idle	screensaver lock-enabled, lock-delay	modelled
Custom background	background picture-uri, -dark	modelled (appearance.wallpaper.light, .dark)
Default favorite applications	shell favorite-apps	modelled, order-sensitive and checked
Login
Greeter logo	login-screen logo	modelled (appearance.loginLogo)
Disable the user list	login-screen disable-user-list	modelled since 2026-10-29 (login.showUserList)
Text banner on the greeter	login-screen banner-message-enable, -text	modelled since 2026-10-29 (login.banner), any length, never from a file
Default session per user	AccountsService XSession	outside: a provisioning choice for one account
Automatic login	/etc/gdm/custom.conf	outside: provisioning; the VM harness uses it for tests
Automatic logout, suspend or shutdown when idle	plugins.power sleep-inactive-ac/battery-timeout, -type	modelled since 2026-10-30 (session.idle.action, .after, .batteryAction, .batteryAfter); a policy that can lose unsaved work, so the pair is explicit
Custom session	a session file with an Exec	refused: arbitrary shell
Multiple keyboard layouts	input-sources sources	modelled since 2026-10-30 (keyboard.layouts, in switch order; the key lands in the distro database, which GDM's profile also reads)
Console keymap	localectl, /etc/vconsole.conf	outside: the graphical session is Wayland and reads input-sources, and the TTY keymap is set by the installer, which is provisioning (architecture.md, "What each layer owns")
Enterprise credentials	FreeIPA or AD join	Milestone 5: identity, never image content
Network and hardware
System proxy	org.gnome.system.proxy mode, PAC, ignore hosts, per-protocol servers	modelled since 2026-10-30 (network.proxy); a password is refused as a secret
Default server list	$HOME/.config/gtk-3.0/servers (XBEL)	outside ($HOME)
802.1X networks	NetworkManager system-connections	modelled since 2026-10-30 (NetworkProfile, ADR 0027): the trust decision in the image, the secret and the identity from the fleet
Default VPN settings	NetworkManager vpn	gap: kind: a second slice, with the plugin's fields typed and no free-form vpn.data
Software
Which search providers answer	search-providers disable-external, disabled	modelled since 2026-10-30 (search.external, .disabled)
Enable machine-wide extensions	shell enabled-extensions	modelled (shell.extensions, plus the platform's catalog)
Custom MIME type	XML under /usr/share/mime plus update-mime-database	artifact: a package or a placed file, not a field
Override the default application	/etc/xdg/mimeapps.list	modelled (applications.*); a user's file still wins
Autostart an application	/etc/xdg/autostart with Exec	refused: arbitrary shell
Typical processes	reference	not a field: a candidate assertion for a check, not intent
Other
Session debugging, custom sessions	logs and session files	outside / refused

What the gaps cost

Three different bills, and conflating them is how a backlog grows without shipping:

• Three fields are cheap: idle logout, XKB layouts and the NFS profile line. Each is a scalar (or two) in GnomeProfile, a lowering rule, a schema entry and a check; no new kind, and the count stays at fifteen.
• Two are kinds: a NetworkManager connection (VPN, 802.1X, proxy) and a polkit action file. The first is needed by real organizations and needs an ADR for secrets at runtime; the second is a security surface and may be refused.
• Three are refused on purpose: single-application mode, custom sessions and autostart. All three are an Exec in a directory; invariant 5 is the reason, and it does not bend for convenience.

Decisions this produces

1. Add the remaining five fields, one PR per group, each with its check; the greeter's two shipped on 2026-10-29, and dim and brightness with them.
2. Open the NetworkManager connection ADR if an organization asks; refuse polkit unless one shows a real need.
3. Keep the refusals written down here rather than rediscovered in review.
4. Correct the roadmap: it claimed dconf defaults and locks covered more than expected. At the audit they covered fourteen guide items exactly and four partially, which is a different claim. The greeter's two, the power pair, Looking Glass and the shield have since added five, so the table above reads nineteen and one.