snc/accept_insecure_cpic is a SAP Parameter attribute which is used to control Accept insecure CPIC-connections to SNC-enabled Server information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
By default, after the Secure Network Communication (SNC) module is
activated, an SAP application server rejects all incoming conventional
(non SNC-secured) CPIC connections from external C programs or SAP
systems.
If you also want to continue to accept insecure CPIC connections (for
example, from old CPIC programs or SAP systems without SNC), you need to
configure that using this switch.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.