SUBJECT_FORMAT

(string, 0 - 252 bytes) Formatting template to format the content of the Subject: header line for display in the SMS message. The global default value for this option is the US-ASCII string “($s)“. See C.3.3.6 Formatting Templates for further details.

See the SUBJECT_NONE option for a description of the handling when there is no Subject: header line or the content of that header line is an empty string.