TP42 is a standard SAP Table which is used to store Assignment of Logical System / ID Number Category data in SAP systems, such as SAP R/3, S/4HANA, depending on the version and release level.
The TP42 table consists of various fields, each holding specific information or linking keys about Assignment of Logical System / ID Number Category data available in SAP. These include LOGSYS (Logical system), MAP_TYPE (Type of BP Identification), IDTYPE (Identification Type)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .