rfc/option_list is a SAP Parameter attribute which is used to control Option list for Remote Function Call (RFC) 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 .
To control the profile parameter:
rfc/dump_connection_info: Trace entries if errors occur
Value range: ,D=<(><<)>-,0,1,2,3<(>><)>
,D=-: Read profile parameter again
,D=0: Deactivate profile parameter
,D=1: Trace for ABAP runtime errors
,D=2: Trace for error messages
,D=3: Trace if exceptions occur
rfc/dump_client_info: Trace entries if errors occur
Value range: ,d=<(><<)>-,0,1,2<(>><)>
,d=-: Read profile parameters again
,d=0: Deactivate profile parameters
,d=1: Work process trace in case of errors
,d=2: Output of the last RFC buffer
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See SAP Parameter Documentation for full SAP documentation for this profile parameter.