The unit list is menu screen which lists creatures on the map. It is accessible with , and is subdivided into four separate screens, whose individual counts are visible at the top of the screen. All have four options: iewing the creature, zooming to the reature location, opening the anager, and emoving a job order (although this is currently only usable for actual citzens).
The first and primary screen is the Citizens screen, which lists your dwarves according to their profession. Dwarves are ordered by category: mining, carpentry, stoneworking, rangers, metalsmiths, jewelers, craftsdwarves, fishery workers, farmers, peasants, active-duty soldiers, children, and finally babies. It shows the current job of each dwarf, highlighted in light blue; repeating tasks are additionally reported with a "/R" at the end, and joblessness is reported with a yellow "No Job." Any administrators will appear in purple where they would appear normally according to their profession. Position in the sublists is determined by the order at which the dwarves arrived. If the unit's name is flashing in this list, it means that they have attained legendary skill level.
The second screen lists livestock. This is useful for quickly zooming to particular animals; most animal management actually happens in the animal status screen.
The third lists "Other". Any creatures that are neither dwarves nor dwarven livestock are listed under Other; this means that the list is populated by visible local wildlife (there may be unseen creatures underground), caravan traders and guards (as well as their pack animals and for-sale animals), exposed thieves and ambushes, the contents of sieges, and anything really scary. This list is most useful for zooming on their location, and lists a few statuses: wild animal (wildlife), domesticated (pets), domesticated (caged) (pets in cages), hostile (thieves), invader (ambushes), uninvited guest (werebeasts, megabeasts, and forgotten beasts), and friendly (traders, the outpost liaison, and caravan guards). This menu is important for keeping track of the local wildlife; regular looks may very well save you from a deadly giant lion attack.
The final list is the Dead/Missing list, which keeps tabs on everything that entered the map and didn't leave. This is the best record of your hunting returns, siege rebuffs, accident victims, and battle casualties. As a dead or missing list, it reports either Deceased or Missing; the missing status will be tacked on the moment a dwarf goes missing, not a week later as with the announcement, making it extremely useful for checking for vampires. For fortresses with long histories, this list may very well be hundreds or even thousands of units long.