W3C mobileOK Checker

The label of each of the following failure messages contains its severity, its category, and a short description of the failure completed by the underlying best practice that triggered the failure.

1. Severity: ; category: ; description: A length property uses an absolute unit ; Best Practice: MEASURES

   Why?

   Using absolute measures in CSS creates layouts that do not adapt to the screen dimensions.

   How?

   Use em or percentage based values in CSS.

   Where?

   Triggered 3 times by the resource under test:

   • Line 3
     … font-size:12px !important
   • Line 3
     … font-size:20px
   • Line 3
     … font-size:16px

   More information

   Severity: low

   Useful improvements are possible.

   Category: Check graphics and colors

   Images, colors, and style brighten content, but require care: devices may have low-contrast screens or may not support some formats.

   Best practice: MEASURES

   Do not use pixel measures and do not use absolute units in markup language attribute values and style sheet property values.

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2. Severity: ; category: ; description: The document does not validate against XHTML Basic 1.1 or MP 1.2. ; Best Practice: VALID MARKUP

   Why?

   The document is invalid XHTML or uses elements or structures that are not allowed in the XHTML Basic 1.1 specification. This is likely to be problematic for mobile browsers who are more sensitive to the structure of the content than desktop browsers.

   How?

   Check the page with the W3C Markup Validator
   While unknown elements are likely to be ignored by browsers, a simple syntax error may invalidate the document to the point where browsers cannot render it anymore. Also bear in mind that checks were run against a tidied version of the document. The tidying process may have modified the structure and semantics of the original document and may have either created new problems or fixed existing ones.

   Where?

   Triggered 4 times by the resource under test:

   • Line 3, Column 510 — Attribute "content" is required and must be specified for element type "meta".
   • Line 3, Column 3246 — Attribute "name" is not allowed for element type "div".
   • Line 3, Column 5362 — Attribute "border" is not allowed for element type "img".
   • Line 5, Column 606 — Attribute value "display:none;" of type NMTOKENS must be one or more name tokens.

   More information

   Severity: low

   Useful improvements are possible.

   Category: Rely on Web standards

   In the highly fragmented market of devices and browsers, standards are the best guarantee for interoperability.

   Best practice: VALID_MARKUP

   Create documents that validate to published formal grammars.

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3. Severity: ; category: ; description: The embedded image or object is not of type image/gif or image/jpeg (image/png) ; Best Practice: CONTENT FORMAT SUPPORT

   Why?

   The document contains images that are not in GIF or JPEG format, or are not correctly served by the Web server. Images in formats other than GIF or JPEG may not work on some mobile browsers.

   How?

   • Convert with an image editor the said images either to GIF or to JPEG, depending on the type of images;
   • Either update the links to these new versions, or use Content Negotiation to have both versions available and served depending on the browser capabilities.

   Where?

   Triggered by http://bits.wikimedia.org/static-1.22wmf4/skins/vector/images/search-ltr.png?303-4.

   More information

   Severity: low

   Useful improvements are possible.

   Category: Rely on Web standards

   In the highly fragmented market of devices and browsers, standards are the best guarantee for interoperability.

   Best practice: CONTENT_FORMAT_SUPPORT

   Send content in a format that is known to be supported by the device.

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4. Severity: ; category: ; description: The CSS style sheet contains rules referencing the position, display or float properties ; Best Practice: STYLE SHEETS SUPPORT

   Why?

   Support for CSS style sheets varies from one device to the other, and cannot be entirely relied upon, especially to position the elements precisely. Floating and absolutely positioned elements should also be avoided on limited screens for usability reason since they may trigger scrolling in two directions.

   Where?

   Triggered 6 times by the resource under test:

   • Line 3
     … display:none !important
   • Line 3
     … display:block
   • Line 3
     … display:block
   • Line 3
     … display:none
   • Line 3
     … float:right
   • Line 3
     … float:none !important

   More information

   Severity: warning

   A warning alerts authors on a point that may have an impact on the user experience on mobile devices and that may be worth checking. A warning does not necessarily mean that something needs to be fixed in the page. Warnings do not affect the score of the page.

   Category: Be cautious of device limitations

   When choosing to use a particular Web technology, consider that mobile devices vary greatly in capability.

   Best practice: STYLE_SHEETS_SUPPORT

   Organize documents so that if necessary they may be read without style sheets.

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5. Severity: ; category: ; description: A matching HTTP response header does not exist for the meta http-equiv element ; Best Practice:

   Why?

   The mobile HTTP delivery chains usually involve more intermediaries than typical desktop chains (e.g. mobile operator gateways). The intermediaries will stick to the HTTP level, and won't dig in the content of the page to check for meta http-equiv elements. For the value not to be ignored, a matching HTTP header should be defined in the HTTP response.

   Where?

   Triggered by the resource under test:

   • http-equiv=content-language

   More information

   Severity: warning

   A warning alerts authors on a point that may have an impact on the user experience on mobile devices and that may be worth checking. A warning does not necessarily mean that something needs to be fixed in the page. Warnings do not affect the score of the page.

   Category: Use the network sparingly

   Web protocol features can help improve the user experience by reducing the impact of network bottlenecks and latencies.

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6. Severity: ; category: ; description: The document does not validate against its declared doctype. ; Best Practice: VALID MARKUP

   Why?

   Not validating against its own doctype can be the sign of a typo in the markup of the page, or that an incorrect doctype was chosen.

   How?

   Check the page with the W3C Markup Validator, or pick an appropriate XHTML doctype.

   Where?

   Triggered 4 times by the resource under test:

   • Line 3, Column 510 — Attribute "content" is required and must be specified for element type "meta".
   • Line 3, Column 3246 — Attribute "name" is not allowed for element type "div".
   • Line 3, Column 5362 — Attribute "border" is not allowed for element type "img".
   • Line 5, Column 606 — Attribute value "display:none;" of type NMTOKENS must be one or more name tokens.

   More information

   Severity: warning

   A warning alerts authors on a point that may have an impact on the user experience on mobile devices and that may be worth checking. A warning does not necessarily mean that something needs to be fixed in the page. Warnings do not affect the score of the page.

   Category: Rely on Web standards

   In the highly fragmented market of devices and browsers, standards are the best guarantee for interoperability.

   Best practice: VALID_MARKUP

   Create documents that validate to published formal grammars.

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7. Severity: ; category: ; description: The CSS Style contains at-rules, properties, or values that may not be supported ; Best Practice: STYLE SHEETS USE

   Why?

   Support for CSS varies from one device to the other. It is relatively safe to assume that mobile devices that support CSS support the CSS Level 1 grammar along with the @media attribute.

   Where?

   Triggered 8 times by the resource under test:

   • Line 3 — Property direction doesn't exist in CSS level 1 but exists in [css2, css21, css3]
   • Line 3 — Too many values or values are not recognized
   • Line 3 — Too many values or values are not recognized
   • Line 3 — Property border-radius doesn't exist in CSS level 1 but exists in [css3]
   • Line 3 — Property -moz-box-sizing doesn't exist
   • Line 3 — Property border-collapse doesn't exist in CSS level 1 but exists in [css2, css21, css3]
   • Line 3 — Property border-spacing doesn't exist in CSS level 1 but exists in [css2, css21, css3]
   • Line 3 — Too many values or values are not recognized

   More information

   Severity: informational

   An informational message is a lightweight warning that alerts authors on a point that may have an impact on the user experience on mobile devices if it is not handled with care. For instance, using scripting is not discouraged but authors should check that the page remains usable without scripting. Informational messages do not affect the score of the page.

   Category: Rely on Web standards

   In the highly fragmented market of devices and browsers, standards are the best guarantee for interoperability.

   Best practice: STYLE_SHEETS_USE

   Use style sheets to control layout and presentation, unless the device is known not to support them.

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