I have created a user defined function called IsIPAddress and it works fine
if I put =IsIPAdress(a2) in column B, for example. It also works if I use
data validation, settings, Allow and select custom and put in the formula
IsIPAddress. If I put an equals sign in it doesn't work =IsIPAddress

I am also trying to see if there are duplicates so I have tried the following:
=AND(COUNTIF($A$2:$A$2000,A2),=1,IsIPAddress)

if I do the compound equation above or the =IsIPAdress I get the following
error "A named range you specified cannot be found".

Why is it looking for a name range when I have a UDF with that name? Is
there a way to prevent this error?

If I put the =IsIPAddress in an adjacent cell B2 (for example) the IP check
works great. Then I put this in the formula using the Validation Icon and it
works,
=and(countif($a$2:$a:2000,a2)<=1,b2)

I would like to have one compound formula using the Validation Icon but
can't seem to figure this out.
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Thank You