I thought this has been discussed, but I must be wrong, since I can't find that discussion.
dynamic_14 and dynamic_2014 both are able to process the same raw hashes.
```
(bleeding-jumbo)run $ cat h
1b3c72e16427a2f4f0819243877f7967$5555hh
778e40e10d82a08f5377992330008cbe$aaaSXB
d6321956964b2d27768df71d139eabd2$123456
(bleeding-jumbo)run $ ./john h --wordlist=p --format=dynamic_14
Loaded 3 password hashes with 3 different salts (dynamic_14 [md5($s.md5($p).$s) 128/128 AVX 480x4x3])
Will run 4 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
test3            (?)
test1            (?)
thatsworking     (?)
3g 0:00:00:00 DONE (2015-01-01 15:21) 300.0g/s 300.0p/s 900.0c/s 900.0C/s test1..thatsworking
Use the "--show" option to display all of the cracked passwords reliably
Session completed
At Program Exit
MemDbg_Validate level 0 checking Passed
(bleeding-jumbo)run $ ./john h --wordlist=p --format=dynamic_2014
Loaded 3 password hashes with 3 different salts (dynamic_2014 [md5($s.md5($p).$s) (PW > 55 or salt > 11 bytes, sse2) 128/128 AVX 480x4x3])
Will run 4 OpenMP threads
Press 'q' or Ctrl-C to abort, almost any other key for status
test3            (?)
thatsworking     (?)
test1            (?)
3g 0:00:00:00 DONE (2015-01-01 15:21) 300.0g/s 300.0p/s 900.0c/s 900.0C/s test1..thatsworking
Use the "--show" option to display all of the cracked passwords reliably
Session completed
At Program Exit
MemDbg_Validate level 0 checking Passed
(bleeding-jumbo)run $ cat john.pot 
$dynamic_14$1b3c72e16427a2f4f0819243877f7967$5555hh:test3
$dynamic_14$778e40e10d82a08f5377992330008cbe$aaaSXB:test1
$dynamic_14$d6321956964b2d27768df71d139eabd2$123456:thatsworking
$dynamic_2014$1b3c72e16427a2f4f0819243877f7967$5555hh:test3
$dynamic_2014$d6321956964b2d27768df71d139eabd2$123456:thatsworking
$dynamic_2014$778e40e10d82a08f5377992330008cbe$aaaSXB:test1
```

It would be great if you wouldn't need to re-crack hashes for dynamic_14 that have already been cracked with dynamic_2014 and vice versa.
(I know that dynamic_14 cannot crack all the hashes dynamic_2014 can crack, e.g., due to max. password length limit. But what prevemts dynamic_14 from recognizing the dynamic_2014 hashes in john.pot when using --show or when loading hashes? Most likely only the fact that nobody implemented it.)