[Description] When signing a message, use cleartext signing with the MIME type "multipart/signed". This is the default if you do not specify any flags to openssl_pkcs7_sign(). If you turn this option off, the message will be signed using opaque signing, which is more resistant to translation by mail relays but cannot be read by mail agents that do not support S/MIME. [Constant] 
PKCS7_DETACHED
P K C S 7 _ T E X T
P K C S 7 _ B I N A R Y
P K C S 7 _ N O I N T E R N
P K C S 7 _ N O V E R I F Y
P K C S 7 _ N O C H A I N
P K C S 7 _ N O C E R T S
P K C S 7 _ N O A T T R
P K C S 7 _ D E T A C H E D
P K C S 7 _ N O S I G S