Quote Originally Posted by antedenise View Post
1. Create a range called "Task_Name" for the column that will hold the id values.
I tried to replicate this and just to clarify, the named range must be limited to the specific cells holding the ID values, not the entire column. Using the entire column gave me #N/A.

It does a lovely job of listing unique values and it will take me a while to figure out how that formula works Also note that there is a known bug in the board that sometimes inserts random spaces into long formulas, and you've got one there. The recommended alternative is to put it in a code box:
=INDEX(Task_Name,SMALL(IF(MATCH(Task_Name,Task_Name,0)=ROW(INDIRECT("1:"&ROWS(Task_Name))),MATCH(Task_Name,Task_Name,0),""),ROW(INDIRECT("1:"&ROWS(Task_Name)))))
meherenow9, it might have allowed us to find a good shortcut if you had mentioned initially that there is a specific set of allowable IDs. My procedural solution and antedenise's formula are for the general case and will handle any data.