If you want to do it within DTM, you can simply make sure 'convert to lowercase' checkbox is checked on every rule.
If you want to do it outside of DTM, you'd want to implement a bit of custom code that would iterate through the data layer and convert everything to lowercase. This page on stackoverflow seemed to have a couple ideas on how to effectively accomplish that:
If you want to do it within DTM, you can simply make sure 'convert to lowercase' checkbox is checked on every rule.
If you want to do it outside of DTM, you'd want to implement a bit of custom code that would iterate through the data layer and convert everything to lowercase. This page on stackoverflow seemed to have a couple ideas on how to effectively accomplish that:
