Meaning of IGNORE_OPTIM_EMBEDDED_HINTS in execution plan

Hi,

My version is 19.12 EE.

I added a dynamic sampling hint to a query causing performance issue and when I retrieved the execution plan using the following statement:

SELECT * FROM table(DBMS_XPLAN.DISPLAY_AWR('g5cr4q9kg8uva'));

I noticed this comment at the bottom of the result:

Hint Report (identified by operation id / Query Block Name / Object Alias):
Total hints for statement: 1 (U - Unused (1))
---------------------------------------------------------------------------
  0 - SEL$4
         U - dynamic_sampling(4) / rejected by IGNORE_OPTIM_EMBEDDED_HINTS

 So if I get it right the dynamic_sampling(4) hint I added was ignored?

I didn't find much information about IGNORE_OPTIM_EMBEDDED_HINTS. The following note is kind of tautological :