You can find user information on this under:
PARTdataManager: Section 2.1.6.4.10, “ Partial search ” in PARTsolutions - User
3Dfindit: Section 3.5.13, “ Partial search ” in ENTERPRISE 3Dfindit - User search
A special index must be generated for this. See Section 1.4.3.6.6.16, “ Geo search index for partial search ”.