0x01: Signature of a canonical text document.
Typically, this means the signer owns it, created it, or
certifies that it has not been modified. The signature is
calculated over the text data with its line endings converted
to <CR><LF> and trailing blanks removed.
I can verify that PGP 2.6.2 and PGP 5.0 do *not* do this for detached
signatures.
I reported that on the OpenPGP list before RFC 2440 was issued, but
for some reason the RFC authors ignored my post.
In PGP, trailing whitespace is removed as part of the clearsig
encoding (which is the only situation where trailing whitespace can
get lost in the transport). It is not part of the signing operation
and should not have been mentioned in the section quoted above.