In the gamemember

Roster

The guild list, with level, class, iLvl, professions and everyone's sheet.

In your game: Roster

What it does: Shows every member, with level, class, iLvl, race, when the data arrived, professions and zone. At the top, cards count members, players, online, average iLvl, average attendance and how many use Guild OS. On the left you filter by online, rank or class. Clicking a name opens the person's sheet, with gear, professions, attendance and loot; right-click opens the action menu.
Who sees it: Everyone, and it cannot be turned off. Mark as Trial and officer notes are officer-only. Promote, demote and remove follow your rank's permissions in the game, and the public note shows for whoever the rank lets edit it.
Where to find it: In the window (J or /gos), Roster tab. The Analytics button, on the tab's bar, opens the guild charts.

Whoever is online always comes first. Untouched, the order is by level, highest to lowest, with ties broken by name.
Search looks in the name, class, zone and rank. Only numbers search by level: 60, 50-59, >=55, or several separated by commas.
Zone only shows for whoever is online. Last seen shows Now for whoever is online; for the others, how long ago their addon's data arrived.
In a narrow window, columns disappear in this order: Zone, Professions, Last seen, Race and iLvl. Member, Lvl and Class never disappear.
The public note, under Add Note in the right-click menu, fits 31 characters without accents (fewer with accents). An empty box deletes the note.
About 10 seconds after you log in, the addon may ask whether your other characters in the guild are alts of your highest-level one. Not now stops it from asking about the same group again.
Your data goes to the guild a few seconds after you enter the game and then every 5 minutes. The Sync button, in the footer, forces it right away.

iLvl, race, professions with levels, gear and stats only show for whoever has the addon and has already sent their data.
Last seen is not the last login to the game: it is the age of the person's addon data.
Race shows in the language of the person's game: Orco for someone playing in Portuguese, Orc for someone playing in English.