+ V3 keys (pgp 2.6x keys) are deprecated. Not only do they rely on md5 for
+ their fingerprint and signatures, they also use the patented IDEA algorithm
+ for encryption. Many people (like caff's author) refuse to sign v3 keys
+ these days.
+
+ If you want to sign v3 keys, sign v3 separately. Batch processing does not
+ work. See README.v3-keys.