This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CD4075B: part marking issue

Part Number: CD4075B

PT#CD4075BM , bought 401pcs of this item , but showing some parts have marking on it but some have no marking . Could anyone tell me what's the reason for this case?