To represent the inflexible organisation of the Imperial Guard, instead of buying one squad per Troops choice, Imperial Guard infantry are chosen as platoons. A platoon consists of a Command Section and two to five infantry squads.
Each platoon counts as a single Troops choice on the force organisation chart. Although they are bought as one Troops choice, the Command Section and squads may fight as separate units, deploying in different parts of the battlefield and fighting as independent units. However, the platoon counts as a single 'choice' when deploying units or rolling for reserves.
Any Imperial Guard squad within 12" of a Command Section may use the Leadership of the Officer in the Command Section for all Morale and Pinning tests. Note that you always use the Officer's Leadership value, even if a Commissar is attached to the Command Section, as long as the Officer is still alive (see the special rules for Commissars that follow...).