Actually, it is Specialist Five In Charge. It was routine for E-4s & E-5s to lead small operations (one or two platoons of CIDG), it was not unusual for E-5s to lead company sized operations. On more than one operation, I was the senior (by rank and/or time in country) USSF. I used the oldSF user name when following the Platoon Leader site. My son is a 2LT in the 10th MTN ID.