SY field read restriction
sy_read_restriction
Description
Finds reads of SY fields not allowed in the current language version
Extended Information
In ABAP Cloud, only 17 system fields may be read; reads of other fields produce a warning.
In ABAP for Key Users, only 5 system fields may be read:
SY-DBCNT, SY-FDPOS, SY-INDEX, SY-SUBRC, SY-TABIX.
https://help.sap.com/doc/abapdocu_cp_index_htm/CLOUD/en-US/ABENSYSTEM_FIELDS.html