Basic Customization > Windchill Customization Basics > Managing Customizations > Best Practices for Adding New Packages and Files > Modeling Recommendations
  
Modeling Recommendations
Sites that use custom modeled classes using Windchill InformationModeler and Java Annotations, may store their new packages and classes under the <Windchill>/src directory structure; however, the packages that are defined should not be stored under the <Windchill>/src/wt or <Windchill>/src/com/ptc directory.
Typically, newly developed packages and classes are stored under the domain name of your company, as described previously.
Some customizations can also be stored under the <Windchill>/src/com/myCompany directory.