Options for controlling the formatting of the generated e-mail.
The subject prefix, by default "PATCH". If set to an empty string ("") then only the patch numbers will be shown in the prefix. If the subject_prefix is empty and patch numbers are not being shown, the prefix will be omitted entirely.
The starting patch number; this cannot be 0. By default, this is 1.
The "re-roll" number. By default, there is no re-roll.