Mark All Instances of Duplicates as 1=YES

[#1]

I have a large set of respondent data where the same respondent may have multiple rows of data (and that is okay), and I want to create a new column that marks a 1=yes if the respondent is a duplicate (for ALL their rows of data, not just the 2nd/3rd/etc. instance), and 0=No if the respondent is not a duplicate (only in 1 row of data). I do NOT want to remove any duplicates. For this example, lets say the column I'm looking for duplicates in is "Phone Number", how can I mark all instances of the same phone number as a duplicate (1=yes) in a new column? (I am using JMP 18)

[#2]

Maybe something like

Col Number(:name, :name) > 1

where :name is your column

Use Value Label column property for making 0 No and 1 Yes (and use nominal modeling type)