icf/shared_memory_cache_off is a SAP Parameter attribute which is used to control switch the ICF memory cache on/off 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 activates/deactivates the memory cache for ICF.
Runtime cache inactive and cache for service determination active
Runtime cache inactive and cache for service determination inactive
Runtime cache and cache for service determination inactive
See SAP Parameter Documentation for full SAP documentation for this profile parameter.