[Users, Groups, Permission] Code/database signing
Like other Office applications, Access 2003 debuted increased paranoia about malicious code. To allow running with a "Macro Security" level other than Low, you can digitally sign your VBA projects (maybe the entire database?). My personal view is that the Office approach to code signing is such a shambles that it's only worth hassling with this if there's a serious potential of accidentally running malicious Access databases. This topic is not covered further in this article.