css-metadata.md
---
layout: page
title: CSS Metadata
order: 14
---
CSS tests have some additional requirements for metadata.
### Specification Links
Specification Links
``` html
<link rel="help" href="RELEVANT_SPEC_SECTION" />
```
The specification link elements provide a way to align the test with
information in the specification being tested.
* Links should link to relevant sections within the specification
* Use the anchors from the specification's Table of Contents
* A test can have multiple specification links
* Always list the primary section that is being tested as the
first item in the list of specification links
* Order the list from the most used/specific to least used/specific
* There is no need to list common incidental features like the
color green if it is being used to validate the test unless the
case is specifically testing the color green
* If the test is part of multiple test suites, link to the relevant
sections of each spec.
Example 1:
``` html
<link rel="help"
href="https://www.w3.org/TR/CSS21/text.html#alignment-prop" />
```
Example 2:
``` html
<link rel="help"
href="https://www.w3.org/TR/CSS21/text.html#alignment-prop" />
<link rel="help" href="https://www.w3.org/TR/CSS21/visudet.html#q7" />
<link rel="help"
href="https://www.w3.org/TR/CSS21/visudet.html#line-height" />
<link rel="help"
href="https://www.w3.org/TR/CSS21/colors.html#background-properties" />
```
### Requirement Flags
<table>
<tr>
<th>Token</th>
<th>Description</th>
</tr>
<tr>
<td>animated</td>
<td>Test is animated in final state. (Cannot be verified using
reftests/screenshots.)</td>
</tr>
<tr>
<td>asis</td>
<td>The test has particular markup formatting requirements and
cannot be re-serialized.</td>
</tr>
<tr>
<td>font</td>
<td>Requires a specific font to be installed at the OS level. (A link to the
font to be installed must be provided; this is not needed if only web
fonts are used.)</td>
</tr>
<tr>
<td>history</td>
<td>User agent session history is required. Testing :visited is a
good example where this may be used.</td>
</tr>
<tr>
<td>HTMLonly</td>
<td>Test case is only valid for HTML</td>
</tr>
<tr>
<td>interact</td>
<td>Requires human interaction (such as for testing scrolling
behavior)</td>
</tr>
<tr>
<td>invalid</td>
<td>Tests handling of invalid CSS. Note: This case contains CSS
properties and syntax that may not validate.</td>
</tr>
<tr>
<td>may</td>
<td>Behavior tested is preferred but OPTIONAL.
<a href="https://www.ietf.org/rfc/rfc2119.txt">[RFC2119]</a></td>
</tr>
<tr>
<td>nonHTML</td>
<td>Test case is only valid for formats besides HTML (e.g. XHTML
or arbitrary XML)</td>
</tr>
<tr>
<td>paged</td>
<td>Only valid for paged media</td>
</tr>
<tr>
<td>scroll</td>
<td>Only valid for continuous (scrolling) media</td>
</tr>
<tr>
<td>should</td>
<td>Behavior tested is RECOMMENDED, but not REQUIRED. <a
href="https://www.ietf.org/rfc/rfc2119.txt">[RFC2119]</a></td>
</tr>
<tr>
<td>speech</td>
<td>Device supports audio output. Text-to-speech (TTS) engine
installed</td>
</tr>
<tr>
<td>userstyle</td>
<td>Requires a user style sheet to be set</td>
</tr>
</table>
Example 1 (one token applies):
``` html
<meta name="flags" content="invalid" />
```
Example 2 (multiple tokens apply):
``` html
<meta name="flags" content="ahem image scroll" />
```
Example 3 (no tokens apply):
``` html
<meta name="flags" content="" />
```
### Test Assertions
``` html
<meta name="assert" content="TEST ASSERTION" />
```
This element should contain a complete detailed statement expressing
what specifically the test is attempting to prove. If the assertion
is only valid in certain cases, those conditions should be described
in the statement.
The assertion should not be:
* A copy of the title text
* A copy of the test verification instructions
* A duplicate of another assertion in the test suite
* A line or reference from the CSS specification unless that line is
a complete assertion when taken out of context.
The test assertion is **optional**, but is is highly recommended to include one.
It helps the reviewer understand
the goal of the test so that he or she can make sure it is being
tested correctly. Also, in case a problem is found with the test
later, the testing method (e.g. using `color` to determine pass/fail)
can be changed (e.g. to using `background-color`) while preserving
the intent of the test (e.g. testing support for ID selectors).
Examples of good test assertions:
* "This test checks that a background image with no intrinsic size
covers the entire padding box."
* "This test checks that 'word-spacing' affects each space (U+0020)
and non-breaking space (U+00A0)."
* "This test checks that if 'top' and 'bottom' offsets are specified
on an absolutely-positioned replaced element, then any remaining
space is split amongst the 'auto' vertical margins."
* "This test checks that 'text-indent' affects only the first line
of a block container if that line is also the first formatted line
of an element."