+=head1 KEY FORMATS
+
+Various different formats are used by the pkcs8 utility. These are detailed
+below.
+
+If a key is being converted from PKCS#8 form (i.e. the B<-topk8> option is
+not used) then the input file must be in PKCS#8 format. An encrypted
+key is expected unless B<-nocrypt> is included.
+
+If B<-topk8> is not used and B<PEM> mode is set the output file will be an
+unencrypted private key in PKCS#8 format. If the B<-traditional> option is
+used then a traditional format private key is written instead.
+
+If B<-topk8> is not used and B<DER> mode is set the output file will be an
+unencrypted private key in traditional DER format.
+
+If B<-topk8> is used then any supported private key can be used for the input
+file in a format specified by B<-inform>. The output file will be encrypted
+PKCS#8 format using the specified encryption parameters unless B<-nocrypt>
+is included.
+