Atom 1.0

<author>

A person construct naming who wrote the feed or an entry — required at one level or the other, which is the rule most feeds break.

An <author> wraps a required <name> and optional <email> and <uri>. It may sit on the feed, on each entry, or both; what is not allowed is neither, and a feed with no author whose entries have none either is invalid however complete it otherwise looks.

Because the requirement can be satisfied at either level, it is easy to remove a feed-level author during a redesign and invalidate every entry at once, with nothing in the document changing shape.

Format: Atom 1.0
Namespace: Atom Syndication Format 1.0
Parent: <feed><entry>
How many: Any number, on the feed or on an entry — but at least one must apply to each entry.

What it contains

namerequiredHuman-readable name.
emailoptional
urioptional

Cardinality and constraints

Any number, on the feed or on an entry — but at least one must apply to each entry.

<name> is required inside it.
Required on the feed, or on every entry individually.
<contributor> has the same shape and is never a substitute for it.

What our validator does

The rule is applied across levels: entries without an author are counted only when the feed has none, and the result is a single error naming how many entries are affected.

Broken and fixed

Both documents below are well-formed XML — that is the point of this corpus — and both are run through the validator on every test run. The verdicts here are what it returned, not what we expect it to.

broken

<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <id>urn:uuid:60a76c80-d399-11d9-b93c-0003939e0af6</id>
  <title>Example</title>
  <updated>2026-08-10T09:00:00Z</updated>
  <link rel="self" href="https://example.com/feed.xml"/>
  <entry>
    <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
    <title>Hen lays egg</title>
    <updated>2026-08-10T09:00:00Z</updated>
  </entry>
</feed>

The feed has no <author>, and 1 entry does not supply one either. RFC 4287 requires an author at one level or the other.

fixed

<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <id>urn:uuid:60a76c80-d399-11d9-b93c-0003939e0af6</id>
  <title>Example</title>
  <updated>2026-08-10T09:00:00Z</updated>
  <link rel="self" href="https://example.com/feed.xml"/>
  <author><name>Ada Lovelace</name></author>
  <entry>
    <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
    <title>Hen lays egg</title>
    <updated>2026-08-10T09:00:00Z</updated>
  </entry>
</feed>

No errors. Warnings may remain — a conforming feed can still be missing a self link — but nothing here is wrong.

Where it reaches

Related elements

All 34 elements

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