The Carriage properties dialog provides 2 data fields for naming Carriages: Name and Notes (optional).

The Name is not optional and is assigned a default name for a new Carriage. Notes are optional and can be anything that helps users understand the model, for instance additional details about the Carriage (manufacturer details, track gauge, gross weight etc).

A visual alert is given when a Carriage name is already used in a Catalogue...

...and in the model: