Comparing a new batch against an old one. A small yellow tablet is different in a way that may be nothing.

A scored oval with a two-letter code is usually a generic but the code is manufacturer-specific.

A batch number and an expiry that are almost up on a new purchase usually means the box was copied.

Imprint is the strongest signal, colour is the weakest, and the shape only narrows the manufacturer.

Light quality ruins more identification photos than anything else. Daylight, no flash.

Happy to be told it is nothing.