Using the GUI, there's an option to view incoming and outgoing files. Using the CLI, you can use stat to view outgoing files (member, modified, missing, external), but I didn't find an option to view incoming files (stale):
accurev stat --outgoing *
The "accurev update -i" is the equivalent of the GUI "Incoming filter". The command will list files that have newer versions in the backing stream.
As an alternate, you could use "accurev stat" and pipe the output to "grep", searching for the word "stale" but this is more cumbersome than simply using the first command.
[Edited for clarity]