tfjern, I think I see the database concept that is giving you some trouble in your database design. Seems you have empirically figured this out but maybe this explaination will help you avoid some future frustration.
Code:
Item Attribute Value
Item1 TAG Important
Item2 TAG Followup
Item3 TAG Important; Followup
Item4 TAG Important Followup
Item5 TAG Important Followup (note the 2 spaces between Important and Followup)
The attribute TAG is of type String (for text information). TAG's value will be anything you can type in the Attributes Value box.
An attribute can only have 1 value...thus the value of Item3's TAG = Important; Followup
It does NOT contain 2 values (value= Important and value= Followup)
Search- UR will parse the Value of TAG into keywords. So a search of "TAG contains keyword Followup" will return items 2,3,4,5.
A search of "TAG contains keyword Important AND TAG contains keyword Followup" will return items 3,4,5.
"Auto-complete values from other items" checked- This creates a pull down list of the values that you entered FOR OTHER ITEMS. So the selection for TAG so far is 'Important', 'Followup', 'Important; Followup', 'Important Followup', and 'Important Followup'<<with the 2 spaces. There will be one entry for each unique value in the other items.
Perhaps after consideration, you might revisit your premise of only using one attribute to label (tag) your items. ie add an attribute= Followup of type Yes/No.
Hope this isn't too wooden or too presumptive, I do have a tin ear......