[Solved] Table with a range of numbers that cannot repeat

[ANCF]

Hey everyone,

Can you please help me with this:

I want to do a table where to a certain fact you put a number in a scale according to how relevant you think it is and i don't want people to repeat a number.

In this case, I want to numbers in a range of [1-11], 1 very relevant and 11 not relevant, be putted in front of a fact without the capability of repeat a number.

Wich is the best way to do this, if possible? Thank you very much

Facts	Importance
Fact 1
Fact 2
Fact 3
Fact 4
Fact 5
Fact 6
Fact 7
Fact 8
Fact 9
Fact 10
Fact 11

[Special-K]

in C2
=IF(COUNTIF(B$2:B$12,B2)>1,"Value already entered","")
and copy down

[ANCF]

Wasn't exactly what i was looking for but this can work.

Thank you