I was discussing with another colleague about what we should be used when an DB entity is referring to another. I don't think there is any good reason to break the practice of putting the Primary Key in the referring entity. However, one of my colleague says: "You should use a surrogate key in the entity, but it is better to put the human-readable natural key in the referring entity. As long it is unique, it is fine and it is easier when you are doing support or maintenance job"
I know it will works, but obviously it is not a good practice you are putting a non-PK unique column as "foreign key", just for gaining a bit of ease in writing SQL during support as we can have less table join.
Though I mentioned the his approach is conceptual incorrect, and causing problem too practically etc, he seems rather trade off correctness in data model in exchange of ease of ad-hoc support jobs. And he said: "I know it is not good practice, but good practice is not golden rule"
Honestly I feel frustrated when dealing with something like this. I know there are always case that we should break some rule or practice, but doubtless it is not such case now.
What will you when you are facing situation like this? Please assume yourself being a senior developer which is expected to contribute in misc development direction and convention.