icf/option_list is a SAP Parameter attribute which is used to control Option list for Internet Communication Framework (ICF) 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:
icf/dump_connection_info: Trace entries if errors occur
Values area
,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
See SAP Parameter Documentation for full SAP documentation for this profile parameter.