What type of clearance does a Reserve Civil Affairs officer (38a) require? Top secret or just secret?

Most officers only require a secret clearance. TS is associated with specific duty assignments and need to know

All CA officers don't have the same job or the same needs for clearance. That is why it says both. The CA BN or BDE can break apart in teams and support other units depending on the need of the situation. CA is there as liaison between the civilians and the unit they are supporting, sometimes foreign units. Other times they stay together to cover a large area. For instance, in Desert Storm my unit split up in teams and supported different units including foreign units working in the Kuwait City area. Some of them were sent into Kuwait City to do battle damage assessments (BDA's) on all public buildings. The rest of the CA BN went in teams to different units working in the city as liaison between the civilians and the unit they were working for. When we were done in Kuwait City my BN was sent to Zakho, Iraq to set up camps for the Kurds returning from Turkey after being attacked in their homes by Iraqis. My whole unit worked together to accomplish this. We set up 2 camps in the middle of nowhere that would hold kup to 30,000 people each. We set up and organized check-in, placing families, handing out food and some household goods. We were there to settle problems and see to unmet needs. We were eventually replaced by the UN, CARE, and many other charitable organizations. Each deployment can be very different than the last.