Documentation is often created in a process of constant change. Therefore project documentation is never complete.

By iterating over a piece of work it gets its final structure step-by-step. In each iteration the same process is applied until the result fully reflects the requirements. The beauty of iteration is that these requirements do not need to be known in advance. The stakeholders will recognize the fitness of the created artifact after the last iteration.

Related Practices

The following practices are related to this principle.

Document State
To set the expectation right it is useful to communicate the state of each document to the collaborating authors and the readers.
Separate Release Cycles
The product and the documentation of the product should be in different release cycles.

Related Principles

The following principles are related to this principle.

Teamwork
Documentation is created and maintained collaboratively by the whole team.

References

More information on this principle.

Iterative Development
Information about Iterative Development on wiki.c2.com.
Iteration
Definition of Iteration on Wikipedia.
Iterative design
Definition of Iterative Design on Wikipedia.