I have in column A a list of say 100 codes of which many may be duplicated.

I wish to produce in column B an automatic list (produced without further
manual input) using all the different codes in column A

i.e. Answers in column A may be XX12, XX13, XX13, YY45, YY45, YY45, ZZ33 & R45

In column B I want to see a list of items (don't know how they will be
sorted) showing XX12, XX13, YY45, ZZ33 & R45 thus avoiding duplications.

Therefore I don't want to produce a drop down list which requires manual
choices in column B.

How do I do this please?

Thanks