Underlying dat data is immutable. It's the constructs built on top that provide mutability. Dat is fundamentally a chain of immutable chunks, some having a spec

Underlying dat data is immutable. It's the constructs built on top that provide mutability. Dat is fundamentally a chain of immutable chunks, some having a special meaning to say what the data means (file/folder) and where to look for it. Once a chunk is there it will 'ever ever change. It is perfectly possible to play with those only.