We have a situation where we want to allow users to create recurring tasks ONLY when the Task Type matches certain values. 

One solution would be to display an alert to users if the Task Type does not match the criteria (starts with "V") and they want to create a Recurring task. But I see that that Alerts are more email notifications than they are alerts that get displayed to users.

The other would prevent them from being able to save if they selected "Yes" for recurring and the Task Type does not match the criteria (start with "V"). I tried creating a Workflow rule, but don't see where I can pick "Repeat" = True.

Is this possible?

Thanks,

Kim