rdisp/build_tid_millisec_based is a SAP Parameter attribute which is used to control Build Transaction Id for transactional 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 .
This parameter configured how the transaction ID (TID) is to be
initialized for the transactional RFC.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.