This is exactly what I was going to post. Everyone my husband works with has all of their information listed in their email signature. It's not "bragging"-- the institution requires everyone to list everything. Perhaps it's not common in other fields, but this seems to be in line with what others are posting for medicine and academia. (It's also interesting to me that everyone seems to agree that it's okay for doctors to list that, but not okay for an MBA. I know several doctors who also list MBA in their email signatures.)
One example where I have seen this countless times is nursing. An RN is an associates level degree, so any nurse with a bachelors is indicated as "RN, BSN". Some positions require a bachelors, some a masters, so this is why the distinction is made. Not only is this listed in their email signatures, it's also printed right on their identification badge that everyone sees.