rdisp/invalidate_memory is a SAP Parameter attribute which is used to control 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 .
Using this parameter defines whether a start range with a byte value is
to be overwritten before releasing internal memory. This is for
troubleshooting. If the parameter value has the value -1, the memory is
not changed.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.