Model, serial, inventory number
The model identifies a product design or variant. A serial number identifies an individual unit. Your inventory number is a label you create for your own records. Keep the three in separate fields.
Transcribe, then photograph
Copy the visible model marking carefully, including punctuation. Take a clear photograph so you can check an uncertain character later. Avoid opening a case to find a label; consult the documentation if the identifier is difficult to locate.
Share only what is useful
For a public collection page, the model is usually enough to explain what the object is. Keep full serial numbers, purchase receipts and personal ownership details in private notes when they do not add anything to the public description.