@Matt Liberty @Tom Spyrou I am bit confused on the "report_annotated_check" in SPEF Based STA. Even though tool not reported any issue while reading spef, but "report_annotated_check" return none are annotated ? Is there is any know issue in Spef based STA or I need additional command ?

% report_annotated_check -list_annotated
                                                          Not   
Check type                        Total    Annotated   Annotated
----------------------------------------------------------------
cell setup arcs                    2746           0        2746
cell hold arcs                     2746           0        2746
cell recovery arcs                 1078           0        1078
cell removal arcs                  1078           0        1078
----------------------------------------------------------------
                                   7648           0        7648

Annotated Arcs

I have even cross-check the OpenSta Example4: https://github.com/The-OpenROAD-Project/OpenSTA/blob/master/examples/example4.tcl It also say's none are annotated ?

Not   
Check type                        Total    Annotated   Annotated
----------------------------------------------------------------
cell setup arcs                       3           0           3
cell hold arcs                        3           0           3
----------------------------------------------------------------
                                      6           0           6

Unannotated Arcs
 setup              r1/CK -> r1/D 
 hold               r1/CK -> r1/D 
 setup              r2/CK -> r2/D 
 hold               r2/CK -> r2/D 
 setup              r3/CK -> r3/D 
 hold               r3/CK -> r3/D

My guess is it is reporting SDC annotation not SPEF annotation