A submenu is a group of choices that flies out beside a row of a menu. It opens when the pointer rests on a row that has an arrow at its right end, and it closes when the pointer moves to a row that has no arrow. Each row is one choice, and a tick marks the choice that is in force.
A submenu opens on the right of its row. When the menu stands too near the right edge of the screen for that, it opens on the left. When the menu stands near the bottom, the group stands up from its row.
The group of Ignore Player in the chat's menu. It offers Add By Target first, then up to ten people who spoke lately in channel chat and are not yet ignored, and last Filters.
The group of Speak on in the chat's menu. It offers Say, Party, Guild, Alliance, Yell and Chat (Channel). A tick marks the one that you speak on now.
The group of Slots in a hotbar's menu. It lists the numbers from 1 to 12, and a tick marks how many slots the bar shows now.
The group of Target in a hotbar slot's menu. It offers Self, Cursor, Current and Stored, and a tick marks what the slot aims at now.
The group for walls in the house designer's storey menu. It offers Show, Transparent and Hide, with a tick on Show.
The group of Worlds in the world map's menu. It lists Felucca, Trammel, Ilshenar, Malas, Tokuno Islands and Ter Mur, with a tick on the world the map shows.
The group of a menu that stands near the right edge of the screen. It opens on the left of its row, because there is no room on the right. It offers Self, Cursor, Current and Stored.
The group of the Animal Form spell's hotbar slot menu. It offers Select, which asks you each time, then rabbit, rat, squirrel, dog, cat, ferret, bullfrog, giant serpent and Cu Sidhe. A tick marks the form in force.
Opening it
Hover over a row that has an arrow in any menu. The group opens beside the row at once.
Moving the pointer to another row with an arrow replaces the group with that row's group.
Moving the pointer to a row without an arrow closes the group.
Choosing a row of the group closes the whole menu. A click anywhere else closes it too.
Using it
Click a row of the group to choose it. The menu closes, and the choice is carried out.
Move the pointer along the group's rows to read them. Moving the pointer within the group keeps it open.