Some time ago, we discussed using the JSR305 annotations. At the time we discussed @Nonnull and @Nullable, and it turned out that those two annotations are "named based" in most analysis-tools; you can make your own org.apache.maven.annotations.Nonnull/Nullable and have a reasonable chance of having tools pick them up. Both findbugs and IntelliJ support this approach. We sort-of concluded that this would be the optimal approach, and since then we promptly did nothing about it :)
I'm very happy that we didn't do anything about it, since I'd now like to re-propose that we actually use
