ms/HTTP/logging_0 is a SAP Parameter attribute which is used to control Specify HTTP logging in Message 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 .
You can use this parameter to control HTTP logging of the message
server. The valid syntax is described in icm/HTTP/logging_<(><<)>xx>.
Only an HTTP logging handler can be defined for the message server.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.