Close Quarters
Source Player Core pg. 153
While you have the necessary training to employ heavy weapons, you believe it's important to keep a backup for when foes get too close. You might be a veteran Veskarium trooper who knows their way around a doshko or a devotee of Zon-Shelyn dealing holy wrath with a painglaive. Blows with heavy close combat weapons hinder your foes just as effectively as when you fire a rotolaser or a missile launcher.
As long as you're wielding a two-handed melee weapon, you meet the requirements for soldier feats that require an area weapon. When using a soldier feat, you can treat any two-handed melee weapon you're wielding as having the area (burst 5 feet), allowing you to area fire with the weapon centering the burst on a corner of a square you occupy, and you are unaffected by attacks with that weapon. You can make a melee Strike with a two-handed melee weapon instead of a ranged Strike with primary target or any soldier feat. In addition, you gain the Whirling Swipe feat.
A close quarter soldier must use the Whirling Swipe feat to gain the benefits of using a reach weapon when making an area attack.
As long as you're wielding a two-handed melee weapon, you meet the requirements for soldier feats that require an area weapon. When using a soldier feat, you can treat any two-handed melee weapon you're wielding as having the area (burst 5 feet), allowing you to area fire with the weapon centering the burst on a corner of a square you occupy, and you are unaffected by attacks with that weapon. You can make a melee Strike with a two-handed melee weapon instead of a ranged Strike with primary target or any soldier feat. In addition, you gain the Whirling Swipe feat.
Paizo Clarifications
When using feats like Whirling Swipe, large sized soldiers can choose any of the 9 corners along the edge of their space.A close quarter soldier must use the Whirling Swipe feat to gain the benefits of using a reach weapon when making an area attack.