icm/HTTPS/trust_client_with_issuer is a SAP Parameter attribute which is used to control trust client with a certificate signed by this issuer 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 .
This parameter is required to transfer certificates in HTTP header
fields from a predecessor (intermediate, for example, SAP Web Dis
patcher) to ICM.
The parameter specifies the intermediate from which the SSL client
certificates that are forwarded in the HTTP header are accepted. The
parameter contains the issuer of the SSL certificate of the
intermediate.
For a description of the two parameters involved, see:
See SAP Parameter Documentation for full SAP documentation for this profile parameter.