Adding a field to a product or an order

The typical need

The requests recur in similar shapes: a free comment per order line, an internal reference on the product page, a case number entered by the customer at checkout, supplier information visible internally only, or regulatory data that must appear on the invoice.

All raise the same underlying question: who enters it, who reads it, and where must the information reappear. A field visible only in admin is quick work. A field entered by the customer at checkout touches the purchase path, validation, the confirmation email and printed documents, which is an entirely different job.

How I approach this kind of work

I start by checking whether the platform already does it. PrestaShop has product features and custom product fields, plus an order comment field; WooCommerce accepts additional data attached to a product or an order without needing a structure to be created. Many requests stop there, and that is a good thing.

When the data must be filterable, validated or reused elsewhere, I create proper storage rather than lodging it in an existing field repurposed for the job. That is where a year of peace is won or lost: data placed in a field designed for something else always ends up clashing with the original function, typically at export or during a migration.

Then I explicitly handle the whole chain: entry, validity checking, admin display, customer display if needed, presence in emails, exports and PDF documents. That list is what separates a genuinely usable field from a field nobody ever looks at.