This was requested back in 2014, but I'd like to revitalize the request.
Being able to use custom tags to transactions would be really helpful. As there's many transactions that I'd like to categorize one way, but still be searchable through multiple other ways.
It would be a very easy concept to implement technically, and would add massive value to the platform.
Since the request was mainly ignored in the past, if the dev team feel it's not worth their time, I'd be more than happy to implement this for you as a free consultant. I just want the feature.