-EVP_EncryptFinal() encrypts the "final" data, that is any data that
-remains in a partial block. It uses L<standard block padding|/NOTES> (aka PKCS
-padding). The encrypted final data is written to B<out> which should
-have sufficient space for one cipher block. The number of bytes written
-is placed in B<outl>. After this function is called the encryption operation
-is finished and no further calls to EVP_EncryptUpdate() should be made.
+If padding is enabled (the default) then EVP_EncryptFinal() encrypts
+the "final" data, that is any data that remains in a partial block.
+It uses L<standard block padding|/NOTES> (aka PKCS padding). The encrypted
+final data is written to B<out> which should have sufficient space for
+one cipher block. The number of bytes written is placed in B<outl>. After
+this function is called the encryption operation is finished and no further
+calls to EVP_EncryptUpdate() should be made.
+
+If padding is disabled then EVP_EncryptFinal() will not encrypt any more
+data and it will return an error if any data remains in a partial block:
+that is if the total data length is not a multiple of the block size.