Global Notice is a short “emergency use only” thing.
For Banner and Pin there are some differences so you should try them.
Note, you want to not have very many Pinned topics as they they tend to not stand out when there are a lot of them.
“when everything is a Pin, nothing is a Pin”
That, and they can occupy all of the “slots” on the category list page. .
Global Notice
They will appear near the top of every page.
They are not topics that can be discussed.
They can not be dismissed.
Banner topic
They will appear near the top of every page unless dismissed.
They may or may not be topics that can be discussed.
They can be dismissed.
Globally Pinned topics
They will appear near the top of the Latest page unless unpinned.
They may or may not be topics that can be discussed.
They can be unpinned.
Pinned topics
They will appear near the top of their category page unless unpinned.
They may or may not be topics that can be discussed.
They can be unpinned.