The following list summarizes all SAP annotations of the Data Definition Language (DDL) of ABAP CDS. SAP CDS annotations are evaluated by SAP frameworks and can be either ABAP annotations or framework-specific annotations.
CDS annotations that are evaluated by ABAP runtime:
To access help for an ABAP annotation, position the cursor on relevant annotation in the DDL source editor and choose F1.
For more information, look here ABAP CDS - ABAP Annotations
CDS annotations that (as a rule) are evaluated during runtime by specific frameworks such as SADL, BOPF, Analytics, or Enterprise Search:
To access help for an framework-specific annotation, position the cursor on relevant annotation in the DDL source editor and choose F1.
For more information, look here Framework-Specific Annotations