# custom_label_0

The custom_label attributes are five free-text fields, numbered 0 to 4, that carry your own segmentation into a feed so campaigns can bid on groupings the channel knows nothing about. Nothing is shown to shoppers: their entire purpose is to let you subdivide a catalogue by margin, season, stock age, bestseller status or anything else you can compute.

- **Canonical URL:** https://www.feedlab.io/knowledge/attributes/custom-label-0
- **Last reviewed:** 16 September 2026
- **Source:** feedlab knowledge base
- **Licence:** free to quote and cite with attribution to feedlab


## Specification

| Property | Value |
| --- | --- |
| Attribute | `custom_label_0` |
| Plain name | Custom label |
| Data type | Text |
| Limit | 100 characters |
| Format | Free text, but treat it as a controlled vocabulary rather than a description. Values are matched exactly and case-sensitively when building campaign groupings, so a handful of consistent tokens such as high_margin or clearance is far more useful than descriptive prose. Each item may hold one value per label, across five independent labels. |


### Example values

- `high_margin`
- `clearance`
- `aw25`
- `bestseller`



### Support by channel

| Channel | Requirement | Field name | Notes |
| --- | --- | --- | --- |
| Google Shopping | Optional | `custom_label_0` | Five labels available, custom_label_0 through custom_label_4. |
| Microsoft Advertising | Optional | `custom_label_0` |  |
| Meta | Optional | `custom_label_0` | Supported for catalogue segmentation in Advantage+ campaigns. |
| OpenAI | Optional | `ads_metadata` | There is no custom_label_0. Custom labelling for Ads is carried under ads_metadata instead. |












## Frequently asked questions

### What are custom labels used for?

They subdivide a catalogue for campaign management. Because they are invisible to shoppers, they can encode anything useful for bidding: margin band, season, stock age, bestseller status, or whether an item is on promotion. Campaigns then target those groupings directly.

### How many custom labels can I use?

Five per item, custom_label_0 through custom_label_4, each holding one value. They are independent, so one can carry margin band while another carries season.

### How do I derive custom labels from Shopify?

They are almost always computed rather than stored. Typical sources are a conditional rule on price or margin, a metafield, tag membership, collection membership, or a comparison between cost and price. Anything you can evaluate per variant at generation time can become a label.




## Primary sources

- [Google: custom_label attribute specification](https://support.google.com/merchants/answer/6324473)