[Dovecot] Non-standard fields?

Hi,

Non-standard fields are mentioned here: http://wiki2.dovecot.org/MailboxFormat/Maildir and they are stated as currently not used.

Questions:

• am I right that if they will be used, they will be key=value pairs, like fields in the base filename? Like: 1035478339.27041_118.foo.org,S=1000,W=1030:2,S,X=12,A=something
• or are they supposed to be flags, like: 1035478339.27041_118.foo.org,S=1000,W=1030:2,S,ABCD
• are there any plans to utilize these?

Thanks,