On your project properties dialog, you will see a "Modules" tab. This lets you select which kinds of module violations you wish to be detected. For example you can define module APIs and have them checked, but not require the module-to-module control (yet).

If "Module API violations" is enabled, then module A can only use the subset of code that is in a "public" region of module B. (Containers can be defined as public using actions on the module sub-menu of the LSM context menu).

Setting "Module requires violations" means that module A can only use any code in module B if there is a direct dependency from the module A node in the LSM onto the module B node. (To add a "requires" dependency, select both module A and module B in the LSM, right-click, add/dependency from A to B).

Setting "Deprecation violations" will cause every dependency onto a deprecated item to be considered a violation. Note that this is in fact independent of the enclosing modules. (The "deprecated" attribute may be picked up from the source code, or can be set by an action from the LSM context menu).