Tag Existing Appointments as Acuity Type

For appointments that get added from outside appointment systems, or even manually added, is there a way to tag them somehow so Acuity will recognize them as an Acuity appointment type? Thereby calculating limits correctly. Currently, if I add an appointment manually to my calendar, it just blocks everything out for that time period. I would like to not have to input everything through Acuity if possible. It would be nice to add a code or something to the existing appointments and then Acuity will recognize them as a specific appointment type and calculate the correct availability through Acuity scheduling. 

Thank you!