Welcome to the Q&A Forum

Thank you very much, Nigel!

Thank you very much.
Is it a very complicated way to solve this issue by using canonical url?

Hi, I have an e-commerce site where I sell greeting cards. Products are under different categories (birthday, Christmas etc) with subcategories (for Mother, for Sister etc) and same product can be under 3 or 6 subcategories, for example:

url: .../greeting-cards/Christmas/product1/for-mother
url:.../greeting-cards/Christmas/product1/for-sister
etc

On the CMS I have one description record per each card (product1) with multiple subcategories attached that naturally creates URLs for subcategories.

Moz system (and Google for sure) picks these urls (and content) as duplicated. 
Any ideas how to solve this problem?
Thank you very much!

Thank you very much, Nigel!