(optional) Defines whether the name of this mailing list should be prepended to the Subject line of mailing list mail. This helps members of the mailing list identify email as coming
from your mailing list, and may help their email program filter and organize email better.
For example, if the original subject is:
Subject: new album from Betsy Smiththe new subject is:
Subject: [jazz-discuss] new album from Betsy Smith