> ## Documentation Index
> Fetch the complete documentation index at: https://help.qrtub.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Creating a Custom Field

> Adding a field to a Collection: the display label, the auto-generated field key and its validation rules, the type, and the ready-made fields you can add instead.

Custom fields are added in the Collection's settings, on the **Fields** tab. A new field
appears on every Item in that Collection immediately, empty until someone fills it in.

## Adding a field

1. Open the Collection, go to its settings, and choose the **Fields** tab.
2. Click **Create Custom Field**.
3. Type a **Display Label** — the wording people see on forms and tables, e.g. "Warranty End
   Date".
4. Check the **Field Key** underneath. It is generated from your label (`warranty_end_date`)
   and you can edit it. It is validated as you type, and the form shows you the binding it
   produces: `{{ item.warranty_end_date }}`.
5. Choose a **Field Type**. See [Custom Field Types](/fields/field-types) for what each one
   gates.
6. Set the options you need — Required, and for a List field Multiple Values and Allow New
   Values. If the type is Text or List you can author its
   [Allowed Values](/fields/allowed-values) here too; if it is UUID you can set up its
   [reference configuration](/fields/reference-fields).
7. Click **Create Field**, then **Save changes** on the settings form. The field is not
   stored until you save.

Behind the scenes the field is given a stable internal ID at this point, which is what lets
you rename it later without touching any data.

## Field key rules

The key is what you write in bindings and conditions, so it is deliberately strict:

* lowercase letters, numbers, and underscores only,
* between 2 and 64 characters,
* no leading, trailing, or repeated underscores,
* not a core field name (`name`, `item_id`, `description`, `tags`),
* not a name QRtub uses internally (`id`, `created_at`, `updated_at`, `image`,
  `destination_url` and similar),
* not a programming keyword such as `class`, `function`, or `return`,
* unique within the Collection.

Whatever the rule, the form tells you which one you broke and suggests a way out — a suffix
like `status_2`, for instance. Because the label auto-generates the key, most of the time you
never type one.

## Adding a ready-made field instead

Under **Add More Fields**, QRtub offers a library of common fields — Item Number, Serial
Number, Category, Type, Subtype, Status, Location, Owner, Equipment Manager, Notes,
Manufactured Date, Parent Item. Clicking one adds it with a sensible type already set (Owner
and Equipment Manager arrive as team-member references, Parent Item as an Item reference), and
you can then click its chip and change anything you like.

The same section lists any field on this Collection that is currently switched off, so it
doubles as the way to bring a disabled field back.

## Ordering fields

Fields show as chips in the order they are used on forms, tables, and CSV exports. Drag a chip
to reorder, then **Save changes**. New fields land at the end.

## Reset to Defaults

**Reset to Defaults** strips the Collection back to the four core fields, removing every
custom field from the configuration. It does not ask for confirmation. Nothing is written
until you press **Save changes**, so leaving the settings form without saving undoes it — but
save, and the fields are gone under the same terms as
[deleting one](/fields/deleting-and-disabling).

## Related

* [Custom Field Types](/fields/field-types)
* [Renaming a Field](/fields/renaming-a-field)
* [Deleting and Disabling Fields](/fields/deleting-and-disabling)
* [Core Fields vs. Custom Fields](/fields/core-vs-custom)