The aim of codification is to put organizational knowledge into a form that makes it accessible to those who need it. It literally turns knowledge into a code (though not necessarily a computer code) to make it as organized, explicit, portable and easy to understand as possible.
An analogous example is the legal system, where the laws and decisions that act as precedents are codified in may texts (and now online and in CD ROM based systems). These references, of course not encompass the tacit skills of lawyers and judges. However, this codified material embodies and makes accessible a significant portion of articulated legal knowledge.