TElPGPKeyFlagsSignatureSubpacket is a descendant of TElPGPSignatureSubpacket class.
This subpacket contains a list of binary flags that hold information about a key.
The following paragraph is taken from RFC 2440 - OpenPGP messages format, part 18.104.22.168.:
«The flags in this packet may appear in self-signatures or in certification signatures. They mean different things depending on who is making the statement -- for example, a certification signature that has the "sign data" flag is stating that the certification is for that use. On the other hand, the "communications encryption" flag in a self-signature is stating a preference that a given key be used for communications. Note however, that it is a thorny issue to determine what is "communications" and what is "storage." This decision is left wholly up to the implementation; the authors of this document do not claim any special wisdom on the issue, and realize that accepted opinion may change.»