Mindoir is a planet that features in the 'Colonist' background for Commander Shepard. It is also mentioned in the "I Remember Me" and "Old, Unhappy, Far-Off Things" secondary assignments.
A human farming colony in the Attican Traverse, Mindoir was raided by batarian slavers in 2170. They slaughtered most of the colonists. Those not lucky enough to die right away were subjected to horrific cranial implants to control them. The Alliance sent in ground forces - Lieutenant Zabaleta among them - to drive the batarians out, but their defenses were too good and the marines were pinned down, forced to watch the suffering colonists but unable to reach them. The atrocity on Mindoir may have been a batarian retaliation against humanity's aggressive colonization of worlds in the Skyllian Verge.
If Shepard has the Colonist back story, the commander was born into a farming family on Mindoir and was sixteen when the raid came. Shepard's friends and relatives were all killed, but Shepard survived and was rescued by an Alliance patrol. Shepard can also meet another survivor of Mindoir, a girl named Talitha suffering from Stockholm Syndrome after marines killed her batarian 'masters'.
If Shepard has the Spacer backstory, Shepard's mother and a Lieutenant Zabaleta are on a ship that responded to the Mindoir raid. The atrocities the slavers inflicted on their victims caused Zabaleta to become afflicted with Post-Traumatic Stress Disorder, which Shepard can later attempt to help treat.
If Shepard has the War Hero backstory, receiving the Star of Terra for acts of heroism on Elysium, Officer Eddie Lang comments that he was on Mindoir when Shepard's medal ceremony was televised, indicating the settlements on Mindoir were rebuilt.
Mass Effect 2
Mindoir has a regular shuttle route to Nos Astra on Illium. Due to security advisories, after several human colonies had been attacked, the route is delayed (canceled) until further notice. If Shepard has the Colonist back story, a news broadcast will reveal that Mindoir has won the right to use Shepard's likeness on its colonial seal.