Glossary/L
Legal line
What it meansThe small print on an ad that qualifies what it says: the end date of an offer, the conditions of a price, the terms behind a claim. It is the part approvers check most closely and the part most often dropped on small sizes, and a needed disclosure should sit close to the claim it qualifies on every device the ad runs on.1
- Also called
- Disclaimer, small print, disclosure, terms line
- Applies to
- Any ad whose claim needs qualifying
- Set by
- Whoever approves legal copy, under the market’s rules
What the guidance asks of it
The FTC’s guidance on digital advertising asks for a needed disclosure to be clear and conspicuous: placed as close as possible to the claim it qualifies, prominent, understandable to the audience, and sufficient on every device or platform the ad can be seen on. When a space-constrained ad requires a disclosure, it should be built into the ad whenever possible; only when that is not possible may it be acceptable to make it clearly on the page the ad links to.1
| On the ad | Ask |
|---|---|
| Placement1 | Is it next to the claim it qualifies? |
| Every size1 | Is it on the small banners too, not only the feed sizes? |
| Legibility2 | Does it have a contrast of at least 4.5:1 against what is behind it? |
| Language1 | Is it in the language of the ad? |
Questions drawn from the FTC’s guidance and WCAG’s contrast measure.12
What it means in practice
Settle the legal line before the layout, not after it. On a small banner it decides how much room every other part has: if it must appear in full, the headline gets shorter, never the legal line smaller. Note its size in pixels on the smallest size, so the approver can judge whether it can be read.
When the offer changes, the legal line usually changes with it, because it names the date or the conditions. Change it on every size at once, and send every size back to whoever approves legal copy.
Common mistakes
- Dropping it from the small banners.Those are the sizes the guidance is most concerned about.
- Shrinking it to fit.Shorten the headline first; a legal line nobody can read does not do its job.
- Leaving it in English on a translated ad.It has to be in language the audience understands.
Sources
- .com Disclosures: How to Make Effective Disclosures in Digital Advertising, US Federal Trade Commission, March 2013. Disclosures close to the claim, on every device the ad runs on, including space-constrained ads.Checked 26 Oct 2026
- Success Criterion 1.4.3, Contrast (Minimum), W3C, Web Content Accessibility Guidelines 2.2. 4.5:1 for text, 3:1 for large text, and logos exempt.Checked 26 Oct 2026