The source definition for an environment file is pretty straight forward, you can have a look in :program:`/opt/environment/modules` to see what they do.
It's possible to conflict with other modules. For example, if you were to load :program:`mrtrix3` and :program:`mrtrix3tissue` you would get an error, because only one implementation of mrtrix3 should be active:
.. code:
[krause@master ~] module load mrtrix3
[krause@master ~] module load mrtrix3tissue
mrtrix3tissue/5.2.8(13):ERROR:150: Module 'mrtrix3tissue/5.2.8' conflicts with the currently loaded module(s) 'mrtrix3/rc3'