We are using tool for our company. Its great, but occasionally we need to white or blacklist certain domains. Example:
if you try to stream foxnews video, it blocks a few domains used with part of the streaming (I assume ad-related requirements). We had to put a few white domains in there to permit that to work.
We got a phish email today to most users in our company, so in hopes to prevent users from doing anything with it, we pi-holed the domain as a precaution.
Putting the reason in might be nice for audit purposes. A year later, we may have no idea why its in there or not.