In case you import a key via WKD (which will typically deliver keys with only one UID) it is not obvious if it's UID is valid or revoked. You can only see this if you check the details of the key before importing it.

If you have imported such a certificate with only a single, revoked UID, the representation in the certificate list shows the status "not certified". Only in the certificate details the uid is marked as "revoked":

And while you are not asked to certify it on import and in the details the "Certify UIDs" is greyed out, it is possible to open the dialog for certification from the context menu of that key in the certificate list. But not to actually certify, as there is no UID to certify.

Gpg on the command line does list such a key, but no UID for it.

We should:

1. Show another status in the certificate list for keys with no usable UID. Either "unusable" or "not usable" and add an explanation in the tooltip in the line of "The owner does not want this user ID to be used any more".

The current tooltip is as misleading as the status designation:

(As it happens, the question of reworking those tooltips in the certificate list came up in another context, too.)

2. Do not offer certification in the context menu of such a key. (Or if we do offer it, at least show an explanation instead of an empty list of user IDs to choose from. Like "No usable UIDs")