Here's a guide of what the system does with each row:

- If the row has an ID specified, and there isn't an ID for that row within the system, it errors out due to the ID not existing.
- If an ID does not exist (left blank), the system tries to match an existing model name.
- If there isn't a model name already that's in the system, it creates one.
- If there already is one model name, it will update that model.
- If there is more than one model in the system with the exact same name, the system will error out since it doesn't know which row to update.
- If there isn't a Category name already that's in the system, it creates one.
(*** Please note, models and categories are case sensitive  so the system will see Blonde and blonde as 2 separate categories.)

If you're doing an initial import from one site to another, you will need to leave the ID values blank so the system will import new model names.