I need to enforce the picklist when creating an event so that manual text input is not possible. I think I need to use the ISPICKVAL function but am not sure what to put as the "picklist_field, text_literal" part.
3 answers
@Kate Williams are you just trying to make the field itself required? or validate specific values selected?
If you just want to make the Picklist required you can use an ISBLANK and TEXT Function like this
ISBLANK(TEXT( Field_Name ))