MCP

There has been some back and forth in my office regarding whether clauses included in task orders have to be in the basic contract and I'm unable to find anything that specifically speaks to this, so I'm beginning to think I've been wrong in my assumptions all these years. I was taught many moons ago when I was learning contracting that in order for a clause to be inserted into a task order that it also had to be included in the basic contract and if it wasn't, that the basic contract needed to be amended before it could be included in a task order. Has anyone else "grown up" under this assumption and if so do you have a reference of where this is specified?