As long as I work with Dynamics NAV as a developer, coding guidelines have always been a point of arguments.
Long, long time ago they were published by Navision as part of the development training materials and documentation.
I know most partners have their own rules and standards, and Microsoft have them too.
They are published
The good news is that they are now updated and published by Microsoft!
You can find them on the Dynamics Community website. Here.
As part of the “How Do I” video series for Design Patterns in Microsoft Dynamics NAV I have also recorded a video.
One of the things I like most about the guidelines is Cyclomatic Complexity. This is a well known concept in computer programming and is now mapped for Dynamics NAV.
While you are implementing these guidelines in your organization, remember to have a look at these implementation patterns. They are great to use and have a big return on investment.