Compression used in an encrypted message

[Avi]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Forgive my ignorance, but is there a way to take a given
encrypted message/file and determine which compression algorithm
was used (and which level)? I know how to set compression
algorithm and level prefs, but I'm curious to see what others
use, if possible.

Thanks,

Avi
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (MingW32) - GPGshell v3.77
Comment: Most recent key: Click show in box @ http://is.gd/4xJrs

iJgEAREKAEAFAk16YNE5GGh0dHA6Ly9wZ3AubmljLmFkLmpwL3Brcy9sb29rdXA/
b3A9Z2V0JnNlYXJjaD0weEY4MEUyOUY5AAoJEA1isBn4Din5uvUA/2qqX7JAcw1C
36V3m9rSWMTt96xQeK6l+/abhwgb7Z6kAQCK0kPjBRiFromrcBueppwKKcvA6Rmw
gO/pjOJhkKxMWQ==
=kVV4
-----END PGP SIGNATURE-----

----
User:Avraham

pub 3072D/F80E29F9 1/30/2009 Avi (Wikimedia-related key) <avi.wiki at gmail.com
>
   Primary key fingerprint: 167C 063F 7981 A1F6 71EC  ABAA 0D62 B019 F80E
29F9
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