As the Org Admin you can set your organization's code on a specific project to be used in mail and document numbering.
When you first register with Aconex, you'll be asked to provide an organization code for your organization.
In fact, the code is project-specific, so you can need to set one for each new project in which your organization participates.
The code identifies your organization on the project, and can be used in document and mail auto-numbering schemes.
When your organization joins a new project, the org code is populated from the Organization Abbreviation set under Organization Details