SY-REPID: System fields are variables but you should always treat them as though they were constants, and only read them. If you change their values, important information for the flow of the program may be lost. All system fields are addressed using SY field name and their types using SYST field name.The system field SY-REPID is not part of SYST or SY. Instead, every program contains the predefined constants SY-REPID and SYST-REPID, which both contain the name of the corresponding program.
Furthermore, there are two predefined types of the same name, SY-REPID and SYST-REPID.
SY-UCOMM: Function code that triggered the event PAI. Every user action that triggers PAI is assigned a unique function code, with one exception: Choosing Enter triggers PAI and different function codes can be transferred to SY-UCOMM:
- If there is an entry in the command field of the standard toolbar, this is transferred to SY-UCOMM as the function code.
- If there is no entry in the command field and a function code is assigned to the ENTER key, this function code is transferred to SY-UCOMM.
- If the command field does not contain an entry and no function code is assigned to the ENTER key, it is empty and the content of SY-UCOMM is not affected.