Am I the only still having issues determining between, MD and DD?

Is there one thing that's a dead give away to say DD for sure?? Or do I just need a better pair of eyes?
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Is there one thing that's a dead give away to say DD for sure?? Or do I just need a better pair of eyes?
Answers
Here's an illustration...
Thanks!
Also, do not look at every coin. Only scrutinize those dates/mm with known DDs. If you think you have one then compare to pics on the internet.
Ok ! I will. Thanks!