On some patent numbers I see an "A1" / "A2" / "B2" etc. suffix after the actual patent number
e.g. "USxxxxxxxxx B2" or "WOxxxxxxxx A1" etc.
What do these suffixes mean? Is there a key somewhere that lists what they mean?
These are kind codes. They are effectively version numbers for published versions of the patent application. Every country has their own set of kind codes, but typically an A code (such as A1) represents a patent application, and a B code (such as B2) represents a granted patent.