W3C mobileOK Basic Tests 1zl

1 Introduction

mobileOK Basic is a scheme for assessing whether Web resources (Web content) can be delivered in a manner that is conformant with Mobile Web Best Practices [BestPractices] to a simple and largely hypothetical mobile user agent, the Default Delivery Context.

This document describes W3C mobileOK Basic tests for delivered content, and describes how to emulate the DDC when requesting that content.

mobileOK Basic is the lesser of two levels of claim, the greater level being mobileOK Pro, described separately. Claims to be W3C mobileOK Basic conformant are represented using Description Resources (see [POWDER]) also described separately.

The intention of mobileOK is to help catalyze development of Web content that provides a functional user experience in a mobile context. It is not a test for browsers, user agents or mobile devices, and is not intended to imply anything about the way these should behave.

mobileOK does not imply endorsement or suitability of content. For example, it must not be assumed that a claim that a resource is mobileOK conformant implies that it is of higher informational value, is more reliable, more trustworthy or is more appropriate for children than any other resource.

1.1 Levels of mobileOK

1.1.1 mobileOK Basic

mobileOK Basic tests are based on a limited subset of the Mobile Web Best Practices. Their outcome is machine-verifiable, hence claims of mobileOK Basic conformance are easy to check.

Content passing the tests demonstrates that the content provider has taken basic steps to provide a functional experience for mobile users.

mobileOK Basic conformance should be considered only a first step towards building a harmonized experience for mobile users. Conformance merely demonstrates that a basic experience is available, interoperable with a large number of mobile devices. mobileOK Basic conformance says nothing about richer, more sophisticated, experiences that may be available, nor does it say anything about whether other guidelines for development of Web content (such as [WCAG]) have been followed.

1.1.2 mobileOK Pro

The (full) mobileOK Pro tests include the mobileOK Basic tests and are based on a larger subset of the Mobile Web Best Practices. These tests are not all machine-verifiable.

Content passing the tests demonstrates that the content provider has taken significant steps to provide a functional experience for mobile users.

However, mobileOK Pro conformance still does not suggest that the most sophisticated mobile user experience possible is available. It implies that a functional experience is available which adheres even more closely to the Mobile Web Best Practices.

Like mobileOK Basic, mobileOK Pro conformance says nothing about whether other guidelines for development of Web content (such as [WCAG]) have been followed.

mobileOK Pro tests will be described separately.

1.1.3 Out of Scope

Some best practices, like TESTING, are advisable but do not meaningfully translate into concrete tests, whether their outcome is machine- or human-verifiable.

The tests assess whether the content can be provided in a way that achieves basic usability, efficiency, and interoperability with mobile devices. The tests should not be understood to assess thoroughly whether the content has been well-designed for mobile devices.

1.1.4 Beyond mobileOK

The best practices, and hence the tests, are not promoted as guidance for achieving the optimal user experience. The capabilities of many devices exceed those defined by the DDC. It will often be possible, and generally desirable, to provide an experience designed to take advantage of the extra capabilities.

Content providers should provide an experience that is mobileOK conformant to ensure a basic level of interoperability. Providers are encouraged to provide enhanced experiences as well when these are appropriate to their application and devices that are accessing them.

1.2 Applicability

The tests apply to a URI. Passing the tests means that when accessed as described in 2.4.2 HTTP Request, resolving a URI will result in mobileOK Basic conformant content that is delivered in a mobileOK Basic conformant manner.

That is, the tests do not apply solely to content or document instances. Many best practices relate not just to the document (e.g. VALID_MARKUP), but to how it is delivered to a mobile device (e.g. CACHING).

mobileOK Basic says nothing about what may be delivered to non-mobile devices.

1.3 Claiming mobileOK conformance

A standard mechanism will be defined that allows content providers to claim that a URI or group of URIs, such as a Web site, conforms to mobileOK Basic or mobileOK Pro. It will be possible to make claims in a machine-processable form. It will also be possible to notify end users of the presence of the claim by means of a human-readable mark.

The details of the mechanism for claiming mobileOK conformance will be described separately.

2 Conformance

2.4 Conduct of Tests

2.4.1 Order of Tests

mobileOK Basic does not prescribe the order in which tests are to be carried out as they may be executed independently. Some tests have been designed to assess aspects of the content that are disallowed by other tests; this is deliberate and is intended to allow testing environments to provide as much information as possible.

For example the test for 3.21 STYLE_SHEETS_USE points out that style sheets should be used in preference to markup elements such as center, even though the center element is also disallowed by the test for 3.4 CONTENT_FORMAT_SUPPORT and VALID_MARKUP.

Creators of implementations of the tests described in this document are encouraged to provide as much information as possible to users of their implementations. Where possible they should not stop on FAIL and specifically they should:

Provide information about the cause of warning or failure (each warn and FAIL is individually identified);
Continue individual tests as far as is possible;
Carry out as many tests as is reasonable.

2.4.2 HTTP Request

The following HTTP request headers inform the server that it should deliver content that is compatible with the Default Delivery Context.

Use the HTTP GET method when making requests, except for 3.10 LINK_TARGET_FORMAT where the HEAD method may be used (See 2.4.7 Linked Resources for a discussion of the POST method).
Include a User-Agent header indicating the default delivery context by sending exactly this header:
```
User-Agent: W3C-mobileOK/DDC-1.0 (see http://www.w3.org/2006/07/mobileok-ddc)
```
Include an Accept header indicating that Internet media types understood by the default delivery context are accepted by sending exactly this header:
```
Accept: application/xhtml+xml,text/html;q=0.1,application/vnd.wap.xhtml+xml;q=0.1,text/css,image/jpeg,image/gif
```
Include an Accept-Charset header indicating that only UTF-8 is accepted by sending exactly this header:
```
Accept-Charset: UTF-8
```
Do not include cookie related headers.
Include authentication information if required (see 2.4.3 HTTP Response). Once authentication information has been included in a request, subsequent requests for the same realm must include authentication information as described in Section 2 and under "domain" in Section 3.2.1 of [RFC2617].
Implementations must support URIs with both http and https scheme components.
Note:
As noted under 2.4.6 Included Resources and 2.4.7 Linked Resources the URIs that are relevant to mobileOK are those that, when represented in an absolute form, have either the http or the https scheme. Requests should not be made for URIs with schemes other than http and https.

2.4.3 HTTP Response

Note:

To allow for self-signature of certificates during testing the signatory of a certificate should not be checked.

Note:

Implementations must support basic and digest authentication.

Note:

Below, note that a 404 or 5xx response for the resource under test does not result in a FAIL in order to allow for the possibility of testing an application's error page.

Note:

If the test below results in a FAIL, do not proceed with further tests. Otherwise, the mobileOK Basic Tests should be applied to the content.

If an HTTP request does not result in a valid HTTP response (because of network-level error, DNS resolution error, or non-HTTP response), FAIL

If the response is an HTTPS response:

If the certificate is invalid, FAIL

If the certificate has expired, warn

If the HTTP status indicates redirection (status code 3xx):

Do not carry out tests on the response

If the response relates to a request for the resource under test, or any of its included resources (see 2.4.6 Included Resources):

Include the size of the response in the total described under 3.16 PAGE_SIZE_LIMIT

Include this response under the count described under 3.6 EXTERNAL_RESOURCES

If there is no HTTP Location header, FAIL.

If the URI identified by the HTTP Location header is a relative URI, create an absolute URI by combining the value of the Location header with the absolute URI of the request to which this is a response, warn

If the resulting URI is not a URI with the scheme http or https, FAIL.

Re-request the resource using the URI formulated above.

If the HTTP status indicates that authentication is required (e.g. status code 401):

If the response relates to a request for the resource under test, or any of its included resources (see 2.4.6 Included Resources):

If authentication information was supplied in the HTTP request (i.e. authentication failed), FAIL

Carry out tests on the response

Include the size of the response in the total described under 3.16 PAGE_SIZE_LIMIT

Include this response under the count described under 3.6 EXTERNAL_RESOURCES

Re-request the resource using authentication information

If the response relates to a request for a linked resource (see 2.4.7 Linked Resources):

Continue with the test (see 3.10 LINK_TARGET_FORMAT , i.e. do not re-request the resource with authentication information), warn

If the HTTP status code is 404 or 5xx

If the response relates to a request for the resource under test, continue with tests on the response and warn

If the response relates to a request for a linked resource (see 2.4.7 Linked Resources), continue with the test (see 3.10 LINK_TARGET_FORMAT ) and warn

Otherwise (i.e. for included resources), FAIL

If the HTTP status represents failure (4xx), other than 404 or a request for authentication (e.g. 401), FAIL

2.4.4 Meta http-equiv Elements

Documents can include meta elements with an http-equiv attribute; these are sometimes considered substitutes for HTTP response headers.

mobileOK Basic test implementations must ignore values specified in such elements, aside from the following:

The Refresh header as specified in 3.1 AUTO_REFRESH and REDIRECTION
The Content-Type header as specified in 3.3 CHARACTER_ENCODING_SUPPORT and CHARACTER_ENCODING_USE
The Cache-Control header as specified in 3.2 CACHING
Check for consistency with HTTP headers, as follows:
For each meta element with an http-equiv attribute:
If a matching HTTP response header does not exist, warn
If a matching HTTP response header exists but its value differs from the content attribute value, warn

2.4.5 CSS Style

Some tests refer to "CSS Style" information. Assemble the CSS Style by using the contents of:

the style attribute of any element (use of the style attribute is deprecated in XHTML Basic 1.1 [XHTMLBasic11])
style elements whose type attribute is "text/css", and whose media attribute is either not present or is present and contains values "all" or "handheld" (case-insensitive).
resources linked via link elements and xml-stylesheet processing instructions, where:
- the rel attribute contains "stylesheet" but not "alternate" (case-insensitive)
- the charset attribute is either not present or is present with value "UTF-8" (case-insensitive)
- the type attribute is either not present or is present with value "text/css"
- the media attribute is either not present or is present and contains value "all" or "handheld" (case-insensitive).
Note:
In the case of xml-stylesheet processing instructions, attribute in this section refers to pseudo-attribute.
resources linked by CSS @import at-rules whose presentation media descriptor is either not present or is present and contains values "all" or "handheld"

In the course of assembling the CSS Style use only those CSS rulesets that are not restricted as to their CSS media type or whose CSS media type specifier contains "handheld" or "all".

2.4.6 Included Resources

Some tests refer to a notion of included resources, which are resources external to the resource being tested and yet vital to rendering that resource and whose URI has the "http" or "https" scheme, when represented in an absolute form. Examples include image and style sheet resources.

When retrieving resources, caching directives should be observed. Multiple references to cached resources are counted only once in regard of page weight (see 3.16 PAGE_SIZE_LIMIT ) and resource count (see 3.6 EXTERNAL_RESOURCES ).

Included resources are defined as those that are referenced by:

the src attribute of img elements
the data attribute of object elements (see notes below)
the href attribute of link elements and xml-stylesheet processing instructions as defined in 2.4.5 CSS Style
images included by background-image and list-style-image properties in the CSS Style ( 2.4.5 CSS Style)
@import directives in the CSS Style - providing they are unqualified as to presentation media type or qualified by presentation media type "handheld" or "all" (case-insensitive) as defined in 2.4.5 CSS Style

Note:

In some circumstances object elements may act as synonyms for other elements such as img and iframe. In these cases it is noted in the relevant section when to regard object elements as equivalents for other elements.

Note:

For nested object elements, count only the number of objects that need to be assessed as discussed in 3.15 OBJECTS_OR_SCRIPT .

2.4.7 Linked Resources

Linked Resources are resources linked to from the resource being tested (other than the resource itself), but which are not vital to rendering that resource whose URI begins with the "http" or "https" scheme when represented in an absolute form.

Linked resources are defined as those that are referenced by:

the href attribute of a (anchor) elements.
the action attribute of form elements whose method attribute is not present or is present with value "get" (case-insensitive).
Note:
Forms with method attribute "POST" (case-insensitive) are permissible in documents under test, but are not checked by mobileOK Basic (posting might cause side effects such as the addition of unwanted records to a database).
Note:
When submitting forms use default values where supplied, otherwise supply empty values.

2.4.8 Validity

Several tests refer to the validity of aspects of a resource. This section defines specifically what this means.

CSS: A resource is considered a valid CSS resource if it conforms to the grammar defined in [CSS], Appendix B (see note below), except that @media at-rules, which are not part of the grammar, are allowed and are not considered invalid. The presence of at-rules, properties or values or combinations of properties and values that are not specified in [CSS] does not constitute a validity failure for CSS. See 3.21 STYLE_SHEETS_USE for treatment of such values. In addition, the @media at-rule and the presentation media qualifiers for the @import at-rule are taken into account when evaluating CSS.
GIF: An image is a valid GIF image if it conforms to the grammar defined in section 25 of the [GIF] specification.
JPEG: An image is a valid JPEG image if it follows the format defined in Annex B of the [JPEG] specification
UTF-8: A resource is considered to be valid UTF-8 if its bytes represent the valid UTF-8 encoding of some string, as defined in [UTF-8], section 4

2.4.9 White Space

Several tests refer to white space. White space has the same definition in this document as in XML. For XML 1.0 [XML10] it is defined in http://www.w3.org/TR/REC-xml/#sec-common-syn as being:

S ::= (#x20 | #x9 | #xD | #xA)+ i.e. the characters SP, TAB, CR and LF.

3 mobileOK Basic Tests

This section describes tests for mobileOK Basic. Tests are organized alphabetically by the Best Practice from which they derive. Where a test derives from more than one Best Practice it is placed according to the one that occurs first in dictionary order.

3.1 AUTO_REFRESH and REDIRECTION

This test does not determine whether the user is able to opt out of refresh.

If a meta element is present with http-equiv attribute value of "refresh",

If the URI specified as part of the content attribute is not the current resource's URI, FAIL

Else, warn

If a Refresh HTTP header is present,

If the URI specified in the header value is not the current resource's URI, FAIL

Else, warn

3.2 CACHING

The purpose of the test is to alert providers to the fact that their content may not be cached, if it would be beneficial to do so.

Note:

Where both a meta element with http-equiv attribute and the corresponding HTTP header are found, the value of the HTTP header must be used - see also note under 2.4.4 Meta http-equiv Elements.

If the HTTP response contains neither an Expires nor Cache-Control header

If no meta http-equiv element is present, referring to those headers, FAIL

Continue the test using the value from the meta content attribute as though it were specified in the appropriate header, warn

If a Cache-Control HTTP header is present and contains value "no-cache", or contains value "max-age=0", warn

If a Pragma HTTP header is present and contains value "no-cache", warn

If an Expires and Date HTTP header are present, and the Expires header specifies a date which is not later than what the Date header specifies, warn

If any cache related header contains an invalid value, warn

If the HTTP response contains a Last-Modified header,

Request the same URI again, adding an If-Modified-Since request header whose value matches that of the Last-Modified response header

If the HTTP response contains a Last-Modified header and its value is again the same, and the HTTP response status is not 304 (Not Modified), warn

If the HTTP response contains an ETag header,

Request the same URI again, adding an If-None-Match request header whose value matches that of the ETag response header

If the HTTP response contains an ETag header and its value is again the same, and the HTTP response status is not 304 (Not Modified), warn

3.3 CHARACTER_ENCODING_SUPPORT and CHARACTER_ENCODING_USE

The DDC is defined to support only UTF-8 encoding, and hence this test fails if a resource is not encoded in UTF-8. The test does not require that resource always be encoded in UTF-8; the test merely checks that the resource is available in UTF-8 encoding, if requested. Resources may be represented using other encodings where appropriate. This test verifies that a DDC-like device which only accepts UTF-8 encoding may access the resource in UTF-8 encoding.

This test requires that character encoding is explicitly specified and recognizes the following methods of specification:

HTTP Content-Type header
```
application/xhtml+xml; charset=UTF-8
```
XML declaration
```
<?xml version="1.0" encoding="UTF-8" ?>
```
meta element that is the first child of the document's head element, and whose http-equiv attribute is "Content-Type", and whose content attribute specifies a character encoding
```
... <head> <meta http-equiv="Content-Type" content="application/xhtml+xml; charset=UTF-8"/> ... 
```

If the HTTP Content-Type header specifies a character encoding other than UTF-8, FAIL

If the HTTP Content-Type header does not specify a character encoding:

If there is no XML declaration, or UTF-8 character encoding is not specified in the XML declaration, FAIL

If the HTTP Content-Type header specifies an Internet media type starting with "text/":

If there is no meta element with http-equiv attribute that specifies UTF-8 character encoding, FAIL

If character encoding is specified in more than one way, and not all values are the same, FAIL

If the document is not valid UTF-8 (see 2.4.8 Validity), FAIL

For each resource specified by 2.4.6 Included Resources:

Request the resource

If the HTTP Content-Type header value of the response starts with "text/" but does not specify UTF-8 character encoding, warn

3.4 CONTENT_FORMAT_SUPPORT and VALID_MARKUP

Note:

In the following, an "html document" is a document that has "html" as its root element.

Note:

In the following, "regardless of its stated DOCTYPE" means that when assessing validity against the XHTML Basic 1.1 and XHTML MP 1.2 DTDs this may be carried out by inserting a DOCTYPE if none is present, or by replacing the given DOCTYPE with the appropriate DOCTYPE for the DTD under test.

Note:

In the following, "a known HTML version" means XHTML Basic 1.0, XHTML Basic 1.1, XHTML-MP 1.0, XHTML-MP 1.1 or XHTML-MP 1.2.

If the document's Internet media type, as specified in the HTTP response Content-Type header, is not "application/xhtml+xml", "application/vnd.wap.xhtml+xml", or "text/html", FAIL

If the document's Internet media type is "text/html" or "application/vnd.wap.xhtml+xml", warn

If the document does not contain a DOCTYPE declaration, FAIL

If the document is not an HTML document, FAIL

If the DOCTYPE is not an XML DOCTYPE, warn

If the document is an HTML document and it has an XML DOCTYPE:

If the document does not declare the html namespace on its html root element, FAIL

If the DOCTYPE refers to a known XHTML version, validate against that DOCTYPE and if invalid, warn

Otherwise (if theDOCTYPE is not known), warn

If ( regardless of its stated DOCTYPE) the document does not validate against the XHTML Basic 1.1 DTD:

If ( regardless of its stated DOCTYPE) it does not validate against the XHTML-MP 1.2 DTD, FAIL

For each included resource (see 2.4.6 Included Resources):

If the response specifies an Internet media type that is not "text/css", "image/jpeg" or "image/gif", FAIL

If an image is required (see also 3.15 OBJECTS_OR_SCRIPT ) and the response specifies an Internet media type that is not "image/jpeg" or "image/gif", FAIL

If the Internet media type is "image/gif" or "image/jpeg", and the resource is not valid (see 2.4.8 Validity), FAIL

If a style sheet is required and the response specifies an Internet media type that is not "text/css", FAIL

If the Internet media type is "text/css" and the content is not valid CSS (see 2.4.8 Validity), FAIL

3.5 DEFAULT_INPUT_MODE

Note:

inputmode is part of [XHTMLBasic11].

For each input element with attribute type whose value is "text" or "password" or whose type attribute is missing:

If the element's inputmode attribute is invalid according to Section 5.2 User Agent Behavior of XHTML Basic 1.1 [XHTMLBasic11], FAIL

If the element's value attribute is missing or empty, and an inputmode attribute is not present, warn

For each textarea element:

If the element's inputmode attribute is invalid according to Section 5.2 User Agent Behavior of XHTML Basic 1.1 [XHTMLBasic11], FAIL

If the element is empty and an inputmode attribute is not present, warn

3.6 EXTERNAL_RESOURCES

Make an inventory of unique included resources, as defined in 2.4.6 Included Resources.

For each such resource:

Request the resource and carry out the procedures discussed under 2.4.3 HTTP Response maintaining a running total of requests made. FAILures that occur in the course of making this assessment contribute to the result of this test.

If the total exceeds 10, warn

If this total exceeds 20, FAIL

3.7 GRAPHICS_FOR_SPACING

The intent of this Best Practice is to avoid using transparent images for spacing. However, small transparent images are often used in e-commerce sites for user tracking purposes. The practice is common enough, and possibly vital enough to the business interests of mobile sites, that it is undesirable to fail sites that use such small transparent images. Therefore this machine-testable test merely warns about the presence of small (at most 2x2) transparent images and FAILs larger ones. It is believed that few if any sites would use transparent images of any significant size for tracking.

For each img element and object element which when retrieved has an Internet media type that starts with "image/":

If all pixels are transparent,

If image height and width are both less than or equal to 2 pixels, warn

If either dimension exceeds 2 pixels, FAIL

If more than one image with all transparent pixels was encountered, warn

3.8 IMAGE_MAPS

If an input element with type attribute set to "image" is present, FAIL

For each img element and object element:

If a usemap attribute is present, FAIL

If an ismap attribute is present, FAIL

3.9 IMAGES_RESIZING and IMAGES_SPECIFY_SIZE

Note:

The height and width HTML attributes specify pixels when they are used as a number. No unit is specified.

For each img element and object element whose type attribute starts with "image/":

If the height or width attribute are missing, FAIL

If the height or width attribute do not specify a size in pixels, FAIL

If the value specified by either the height or width attribute is greater than the corresponding dimension of the image, warn

If the value specified by either the height or width attribute is less than the corresponding dimension of the image, FAIL

3.10 LINK_TARGET_FORMAT

Note:

404 and 5xx HTTP status do not result in failure when conducting this test.

Note:

The document body of linked resources is not examined.

For each linked resource, as defined in 2.4.7 Linked Resources:

Request the resource

If the Content-Type header value of the HTTP response is not one of the Internet Media Types listed in the Accept header in 2.4.2 HTTP Request, warn

If the Content-Type header value of the HTTP response does not specify a charset parameter, or does but it is not consistent with the value of the Accept-Charset header in 2.4.2 HTTP Request, warn

For each document internal reference (links in the document under test that refer to the document itself):

If there is no target for the reference or it is invalid (e.g. '#'), warn

3.11 MEASURES

Note:

The intrinsic size of images must be specified as attributes of the img element and not as CSS properties (see 3.9 IMAGES_RESIZING and IMAGES_SPECIFY_SIZE)

Note:

Only CSS Level 1 properties are considered in this test.

For each CSS Level 1 property in the CSS Style ( 2.4.5 CSS Style) whose value is a numeric measure of length stated together with a unit:

If the value is non-zero and the unit is not "em" or "ex" (and the value is not a percentage), and the property is not a margin, border or padding box property, FAIL

3.12 MINIMIZE

Note:

Extraneous white space characters in script and in CSS are not considered in this test. Such an extension may be considered in a future revision of this specification.

Count number of white space characters (see 2.4.9 White Space) in a sequence of more than one white space character (not counting the first), which exist outside of a pre, style, script element, or XML comment

Add to this count the number of characters comprising XML comments. This total is the number of extraneous characters in the document.

Count total number of characters in document

If the number of extraneous characters exceeds 10% of the count of characters in the document, warn

If the number of extraneous characters exceeds 25% of the count of characters in the document, FAIL

3.13 NO_FRAMES

If the document contains a frame , frameset or iframe element or it contains an object element which when retrieved has an Internet media type that starts with "text/", "application/xhtml+xml" or "application/vnd.wap.xhtml+xml", FAIL

3.14 NON-TEXT_ALTERNATIVES

This test does not determine whether the alternative text is meaningful.

Note:

An empty alt attribute is acceptable and signifies that there is no meaningful textual alternative, for example for images that are purely decorative.

For each img element:

If an alt attribute is not present or contains only white space, FAIL

3.15 OBJECTS_OR_SCRIPT

This test does not determine whether the document is still usable without the objects or scripts.

If a script element is present, warn

If any element has an "intrinsic event" attribute (currently onload, onunload, onclick, ondblclick, onmousedown, onmouseup, onmouseover, onmousemove, onmouseout, onfocus, onblur, onkeypress, onkeydown, onkeyup, onsubmit, onreset, onselect, onchange), warn

For each a and link element:

If the value of the href attribute begins with the "javascript:" scheme, FAIL

If an applet element is present, FAIL

Set the context to the root element and apply the Object Element Processing Rule

3.15.1 Object Element Processing Rule

For each object element that has no object element ancestor in this context (excepting the context node itself):

Retrieve the object (ignoring the type attribute)

If the content type of the retrieved object is not "image/jpeg" or "image/gif"

If the object element is empty, warn

If the content of the object element consists only of white space, FAIL

For each img element that has no object element ancestor in this context:

If the content type of the img element is not "image/jpeg" or "image/gif", FAIL

Reapply this rule using the current object element as the context

3.16 PAGE_SIZE_LIMIT

If the size of the document exceeds 10 kilobytes, FAIL

Add the size to a running total

For each included resource, as defined in 2.4.6 Included Resources:

Request the referenced resource

Add the size of the response body to the running total (for object elements count the size of objects retrieved under the "Object Element Processing Rule" whose type attribute is not specified, and those whose content type is either "image/jpeg" or "image/gif" irrespective of whether the type attribute is specified)

If the total exceeds 20 kilobytes, FAIL

3.17 PAGE_TITLE

This test does not determine whether the title is meaningful.

If a title element is not present in the head element, or is empty, or contains only white space (see 2.4.9 White Space), FAIL

3.18 POP_UPS

For each a, link, form, and base element:

If a target attribute is present,

If its value is not one of "_self", "_parent", or "_top", FAIL

3.19 PROVIDE_DEFAULTS

In addition, a human-verifiable test is needed here to verify whether such elements could be replaced with alternative control elements.

For each radio button group within a form element ( input elements with type "radio" that share the same name attribute value):

Check that exactly one input element within this group has its checked attribute set to "checked", and if this is not the case, warn

For each select element:

If there is no nested option element whose selected attribute is set to "selected", warn

If there is more than one option element whose selected attribute is set to "selected", and the multiple attribute is not set to "multiple", warn

3.20 STYLE_SHEETS_SUPPORT

In addition, a human test is needed here to verify whether the page is readable without a style sheet.

If the CSS Style ( 2.4.5 CSS Style) contains rules referencing the position, display or float properties, warn

3.21 STYLE_SHEETS_USE

This test looks for elements in the Text Extension module defined by [XHTMLModularization], some of which are not supported in XHTML Basic [XHTMLBasic11]. It also looks for commonly-used elements and attributes that were deprecated in HTML 4, and are not supported, or are deprecated, in XHTML Basic.

Note:

This test does not require that any CSS styles be used, since in some cases, no presentation information is required at all (for example, a simple page of text).

Note:

The tests on CSS property values only apply to properties defined by CSS Level 1; other properties are ignored for the purposes of this test.

If the document contains any basefont, bdo, center, del, dir, font, ins, menu, s, strike or u elements, FAIL

If the document contains any b, big, i, small, sub, sup or tt elements, warn

If any element has a style attribute, warn

If there is CSS Style ( 2.4.5 CSS Style)

If all styles are restricted to media types other than "handheld" or "all" by means of @media at-rules, warn

If the CSS Style contains at-rules (other than the @media at-rule, and the media list of the @import at-rule), properties, or values that are not recognized as being specified in CSS Level 1, warn

If the CSS Style contains a property with a value that is inappropriate to it, warn

If the CSS Style contains a property with a value that requires a unit or a percentage:

If the unit (or percentage) is not present, warn

If the unit (or percentage) is inappropriate to the value, warn

3.22 TABLES_ALTERNATIVES

If a table element exists, warn

3.23 TABLES_LAYOUT

This test does not catch all cases where tables are used for layout purposes.

For each table element:

If it contains at most one tr element, FAIL

If no tr element contains more than one td element, FAIL

For each nested td element:

If the element contains only an image (or equivalent object) whose actual dimensions are 2x2 or less, FAIL

3.24 TABLES_NESTED

For each table element:

If it contains a table element, FAIL

Best Practice	mobileOK Basic	mobileOK Pro
ACCESS_KEYS		X
AUTO_REFRESH	X	X
AVOID_FREE_TEXT		X
BACKGROUND_IMAGE_READABILITY		X
BALANCE
CACHING	X
CAPABILITIES
CENTRAL_MEANING
CHARACTER_ENCODING_SUPPORT	X
CHARACTER_ENCODING_USE	X
CLARITY
COLOR_CONTRAST		X
CONTENT_FORMAT_PREFERRED		X
CONTENT_FORMAT_SUPPORT	X
CONTROL_LABELLING		X
CONTROL_POSITION		X
COOKIES		X
DEFAULT_INPUT_MODE	X
DEFICIENCIES
ERROR_MESSAGES		X
EXTERNAL_RESOURCES	X
FONTS		X
GRAPHICS_FOR_SPACING	X	X
IMAGE_MAPS	X
IMAGES_RESIZING	X
IMAGES_SPECIFY_SIZE	X
LARGE_GRAPHICS	X
LIMITED		X
LINK_TARGET_FORMAT	X
LINK_TARGET_ID		X
MEASURES	X
MINIMIZE	X
MINIMIZE_KEYSTROKES		X
NAVBAR		X
NAVIGATION		X
NO_FRAMES	X
NON-TEXT_ALTERNATIVES	X	X
OBJECTS_OR_SCRIPT	X	X
PAGE_SIZE_LIMIT	X
PAGE_SIZE_USABLE		X
PAGE_TITLE	X	X
POP_UPS	X
PROVIDE_DEFAULTS	X	X
REDIRECTION	X
SCROLLING		X
STRUCTURE		X
STYLE_SHEETS_SIZE
STYLE_SHEETS_SUPPORT	X	X
STYLE_SHEETS_USE	X
SUITABLE		X
TAB_ORDER		X
TABLES_ALTERNATIVES	X
TABLES_LAYOUT	X	X
TABLES_NESTED	X
TABLES_SUPPORT
TESTING
THEMATIC_CONSISTENCY
URIS
USE_OF_COLOR		X
VALID_MARKUP	X