Specifies if whitespaces must be trimmed from the signature.
Several versions of PGP have bug in their implementations that results in creation of incorrect text signatures.
The following paragraph is taken from RFC 2440:
«PGP 2.6.X and 5.0 do not trim trailing whitespace from a "canonical text" signature. They only remove it from cleartext signatures. These signatures are not OpenPGP compliant -- OpenPGP requires trimming the whitespace. If you wish to interoperate with PGP 2.6.X or PGP 5, you may wish to accept these non-compliant signatures.»
One can say that this bug also exists in PGP6.5 and PGP8.0 implementations. It is a good idea to set this property to True if you want to interoperate with those versions of PGP. Set this property to False if you need to create OpenPGP-compliant messages.