I was just working a series of leads with the same follow up activity of scheduling a call with information of why I was scheduling the call.
I then added the reason to the drop down list for "Regarding" and noticed that the information was truncated when selecting it while I could paste the full reason in both the actual regarding field and when creating the drop down.
The activity is a custom activity; however, I also tested this with a standard activity.
John Purdy ACT! Premium V. 22.214.171.124 Update 3 HP ENVY 17m, 16GB, & Office 365, 32bit, 500GB SSD. ACT CRM Advisor