Ceska verze

Dogma W4

Version 1.0 | OBSOLETE (see current version) | 1 October 2002
Current version and other information: http://dogma.pixy.cz

Abstract

Dogma:
an authoritative and precisely formulated statement of a doctrine that is advanced, not for discussion, but for belief; a system of principles or doctrines, or a single doctrine prescribed by some authority; an established and widely held principle or opinion.
W4:
Worth World Wide Web
Worth:
good, valuable, important enough to warrant; having a monetary value of; having wealth and property amounting to

Proclamation of Dogma W4

A lots of texts has been written about worthful and universally accessible web. We, as webdesigners, are understanding one example is better than thousands of books. Therefore, this web site honours the Principles of Dogma W4. These principles are not essential for good web. However, honouring them reduces hazards off less accessibility and usability of the web with no compromise.

Principles of Dogma W4

  1. HTML 4.01, XHTML 1.0, or later is used for documents. Every information expressed by the document must be formed by its textual content. [see Details - Document Format]
  2. If the specification allows more types of document, the Strict type is used. The code of the document contains no errors and it is fully valid according to the specification. [see Details - Document Code]
  3. The content of the document is semantic structured and hierarchic ordered. The structure of the code flows from the leading message to details, other information follows them. The hierarchy is established by headings of several levels. Exactly one top-level heading must by contained in the document. It may be preceded only by information needful for understanding the context of the document, by links into the document, and by information serving for operations with the content and its layout. [see Details - Document Sructure]
  4. If other encoding than default is used for the document, it must be defined in <head> section of the document, even if it is sent in the http-header. The header must also contain name(s) and e-mail address(es) of the author(s) of the code, or link to a document containing them. [see Details - Header]
  5. Document body must not contain any data without informational value. Images whose informational value is formed only by displaying a text must not occur in the document. Tags and content predestinating certain way of presentation are forbidden. [see Details - Illegal Content]
  6. The homepage must clear describe the content and the essential message of the presentation. The homepage contains viewable e-mail address of the administrator, or link to a document containg it. [see Details - Homepage]
  7. If more than one document constitutes the presentation, each document must contain lucid and easy accessible navigation. The navigation must contain at least a link to the homepage. Design and position of the navigation must be same in each document. The homepage only may use different form of navigation. Large documents must be divided into sections, each section must be linked from the beginning of the document. [see Details - Navigation]
  8. Links must clear describe and identify their targets. Same links must have same target, descriptions of links with different targets must be different. If the activation of a link causes other action than a modification of the document's content, the user must be warn before activating the link. The author must not disable underlining of textual links. Style of dynamic states must not cause reformating of the document. [see Details - Hypertext Links].
  9. Tables may be used only for displaying tabular data, using them to lay out elements is forbidden. Tables must be inspectional, readable and accessible. The summary (or link to it) must occur in the beginning of each table. [see Details - Tables]
  10. Recommending or disallowing certain type or brand of output device for the document is forbidden. If the document is prepared for specific device, a generally accessible alternative must be linked in the document, e. g. by a <link> tag. [see Details - Devices]
  11. All data impacting the document layout, but not forming parts of its content, must be placed in external files and linked within the document's <head>. [see Details - External Data]
  12. The document must not offer any information accesible only with an extension beyond the (X)HTML resources (attached scripts and styles, embeded objects etc.). Making any extension unaccessible must not diminish the usability of the document, neither make a part of its content inaccessible. These extensions may only cause modifications of document itself. Any inroad on user interface and preferences is forbidden. [see Details - Extensions]
  13. Scripts and Cascading Style Sheets (CSS) must be degradative: unsupported function, property or construction must not diminish usability of the document. [see Details - Extension Support]
  14. Within the visual presentation of the document, all color combinations must be usable regardless of device's or user's possibilities. Text backgrounds must be formed only by solid monochromatic area, overlapping the text enough on each side. If the background has different color than black or white, the text must be black or white. Color text on color background may be formed only by textual links. The distance between text and background percentual brightnesses must be at least 50. [see Details - Colors]
  15. Blocks of text must not touch or overlap. Explicit space must be between adjacent blocks. No font may be defined smaller than x-small, neither smaller than 85 % of the base font size of the document. The font size must reflect the content hierarchy. If the font-family is defined in CSS, the last value in the list must be a generic family. [see Details - Text]
  16. The autor may avow his honouring these Principles in the document. [see Details - Avowal]

Details of Dogma W4 Principles

Following text explains and specifies several articles. These deliminations are as normative as rules specified in the Principles.

  1. Document Format:
    1. Tags and constructions not known in previous versions of the language must be used with respect of backward compatibility.
    2. Information is formed only by textual content of documents. Another kind of content is allowed only as a supplement. Its design or didactic value, and not the informational value, may be higher. E. g. the message of an image or object is described in its alt atribute, its visual presentation is accepted as supplementary information; tables are presented by (X)HTML resources, link to the table in another format (CSV, XLS, etc.) may be offered only as the alternative, etc.
    3. If an information cannot be published by (X)HTML, it must be placed in an external file, using a generic format whose proccessing isn't conditional on buying a commercial product. Along with this, the user must obtain a comprehensible description how to proccess this information. [see also Hypertext Links].
    4. If the information can not be universally accessible (download of a platform-specific application, proprietary files of a particular application etc.), the file may be linked, only if the link is followed by a text describing the equipment, the application and the platform necessary for proccessing this information. However, this method is allowed only if the information cannot be saved in generic and accessible format.
    5. Information in text files (TXT) are allowed only if this file is served with MIME-type text/plain, with us-ascii encoding (the text contains only ASCII chars 0-127) and line breaks are made by CR+LF sequences. Text files using another charset may be used only if the link to them is followed by viewable information about used encoding.
  2. Document Code:
    1. Correct DOCTYPE is set at the document beginning.
    2. Transitional and Frameset document types are forbidden.
    3. The code is valid according to the language specification. Software validator's output can be only a clue, not the affirmation.
    4. If HTML is the document language, tag and atribute names are lowercase.
    5. Every atribute value must be quoted.
    6. If the specification allows double ["] or single ['] quotes, double quotes are used.
    7. The code must not contain tags and constructions unrecommended by the specification.
  3. Document Structure:
    1. Each document contains this minimal construction:
      <html><head><title>Title</title></head><body>[identification]</body></html>
    2. The identification of the document is formed by the top-level heading (<h1> tag in HTML and XHTML 1). Its content introduces the message of the document. Instead of one top-level heading, the indentification may be formed by hierachic sequence of headings of several levels (e. g. website title - section title - document title), starting with the top-level heading. In this case, every level must be used exactly once, no level can be left, and lower levels cannot precede higher levels in the document structure.
    3. The content of the <title> tag must briefly and pregnant describe the document, even if it's used later, without the document context (link to the document, name of a bookmark etc.)
    4. The last heading level used in document identification establishes the top limit for other headings used later in the document. The level of all other headings must be lower and it must reflect the content hierarchy.
    5. The essential message of the document must follow the identification.
    6. The document identification may be preceded only by:
      • information introducing the document's content (e. g. a motto)
      • information locating the document in the site context, e. g. a sequence of preceding documents in the website hierarchy, etc.
      • links into the document (short table of contents, an index, links to information placed bellow the document message etc.)
      • information serving for operations with the content and its layout (a pick of document language or encoding, user preferences, links to altrenative proccessing of the document, link to the help etc.)
    7. Any other information must be placed in the code bellow the main message of the document (links to relative documents, additional information, global navigation etc.)
  4. Header:
    1. Document encoding is set by a meta-tag with these parameters:
      http-equiv="Content-Type" content="text/html; charset=charset_code"
      Charset code is an identification string prefered by IANA.
    2. If the XML declaration figures in the document, it must also set the encoding, equivalent to the meta-tag data:
      <?xml version="1.0" encoding="charset_code"?>
    3. Each author of the code is given in a single meta-tag, at least in this form:
      name="author" content="[part]: name & surname; valid e-mail address",
      where the [part] is one or more keyword describing part of the code the author participated with:
      • code - the author of the document code
      • scripts - the author of scripts used within the document
      • style - the author of stylesheets used within the document
      • all - the author of all used codes
    4. Authors may be specified in separate document, linked in header by a <link> tag.
    5. Names of author(s) must be viewable only with ASCII chars. If author's name uses characters from other charset, an generally used english transcription must be given, at least as the altrenative.
    6. Authorship of other parts of the document (authors of the content, design etc.) is out of scope of these principles.
    7. Other metadata and their profile may be added to these Principles in the future.
  5. Illegal Content:
    1. Tags and atributes predestinating element's formating (<b>, <i>, <big>, or atributes bgcolor, align, etc.) are forbidden, even if the specification allows them. Only tags marking semantic structure of the content and type of its parts (citation, address, emphasis, etc.) may be used.
    2. The content of the document doesn't refer to its possible layout in any way ("...in right column", "bottom menu", "see red box", etc.). Verbal references like "see above" or "see bellow" without hyperlinks are allowed only in the content of document's main message, if this content uses continuous formating, and only if they are refering to same, next, or previous block of text (paragraph). Other references in this form are forbidden.
    3. Author must always presume presentation of the document on any device with any user preferences. Preconceiving only one of all possible kinds of document presentation is forbidden ("right-click", "move mouse cursor to...", "press F15" etc.), if this information may be presented on another device. Texts like this (e. g. the help or hints) must be followed by specification of relevant platform/device, or the author must assure the text will be published only within proper device.
    4. All <img> tags in the document are linked only to images having visual informational value, relevant to textual content of the document.
    5. Images displaying text are allowed only if the grafic presentation of this text is the intergrant part of their message (logotypes, examples of typography etc.). Even then, the document must contain (at least alternative) textual information describing the message of this image.
    6. Above the semantic structured content the document may containt only neutral tags <div> and <span> and atributes class and id. Values of these atributes use only lowercase letters [a-z], digits [0-9] and minus [-] and underscore [_] signs; they start with a letter. Different elements use different id, there is no element with two different id.
  6. Homepage:
    1. Presentation of an organization (a company, an institution, a syndicate etc.) must contain its name, logotype (if it's used in the presentation) and contact informaction (or link to it) on the homepage.
  7. Navigation:
    1. In document code, global navigation (through documents) must be placed bellow the main message of the document. However, it can be displayed everywhere. The navigation must have same form and position in each document when same type of presentation is used.
    2. Links into the document itself must be given at its beginning. One of these links can be link to the global navigation.
    3. Standalone global navigation is not neccessary if the beginning of the document contains document's location in sequence of website hierarchy [see Site Context]. Items of this sequence must be made by links to proper documents, and first item must point to the homepage. E. g.: [homepage] > [products] > [section 1] > this document.
    4. A navigation depending only on scripts operation is not allowed. It must be sufficient with (X)HTML resources only.
    5. Links inside navigation must be marked with an <a> tag.
  8. Hypertext Links:
    1. The text of the link (or the alt atribute of an object forming the link) must clear describe the target of the link. Links like "click <a>here</a>" are forbidden.
    2. If two links use same description, their target must be same. However, the title atribute can be counted in in well-founded cases:
      • if numeric, or alphanumeric codes, symbols or pictograms form the content of links and their meaning is explained enough (or explanatory notes are linked within the document). In this case, the target of the link must be described in the title atribute (same targets have same description, different targets have different description).
      • if links with same content and mutualy exclusive targets are used in continuous list of several items. The target of each link is described in the title atribute, and it must be different in each list item. E. g. links like [details], [add to the shopping basket] in products table; [full story] at the end of each example in list of stories, etc. Anyhow, same links must cause same type of action for each item in the list, they must have same form and position in every item, and their descriptions must be mutualy different.
    3. Links into automatically numbered lists (e. g. <ol>) must not contain value which could be generated for the target item (e. g. "item 9.2.1").
    4. Targets of links into the dokument must be as close as possible to the linked content. The target must be easy observable in the surrounding context.
    5. Modifications of document's content allowed as a result of activating a link (or other user's action) mean only changes within the space enclosed for actual document (e. g. the content of active browser window). User's action may cause:
      • moving to another part of the content (links into the document)
      • loading another content (links to other documents)
      • changing the form of the content (changing the layout, loading another stylesheet)
      • displaying/hiding a part of the content (DHTML)
    6. If the activation of a link (or other user's action) causes any change outside the document's content, e. g. opening new window, closing actual window, starting of a download etc., the user must be warned before he activates the link. Links to external downloadable files must be followed by information (visible text, title atribute of the link, etc.) saying the file size, the file type and how to proccess the file. If type of the file is different than (X)HTML, TXT, GIF, JPG, or PNG, the proccessing application and link to its download must be specified, too [see also Document Format].
    7. In CSS, setting text-decoration:none for a:link and a:visited elements is forbidden. If author specifies style for links' dynamic states (:hover, :active, :focus), he must not use same style for different states. All states must be styled mutually different, and it can't be done only by setting border, padding and margin properties.
    8. Styles for dynamic states of elements must not set properties influencing position of surrounding elements. Especially, they cannot redefine properties like font-size, font-weight, margin and display.
  9. Tables:
    1. Any presentation of a table must not cause merging of adjacent cells. Adjacent cells must be formated with frames, markedly different backgrounds, or with sufficient gap between their content.
    2. Assigning zero value to table's atributes border, cellpadding, or cellspacing is forbidden.
    3. The summary atribute is mandatory in every table. It must contain description of structure, purpose and content of the table.
  10. Devices:
    1. Especially, expressions like "optimized for" are forbidden.
    2. Author mustn't make the document's content inaccessible, e. g. as the result of detecting target device parameters. Automatic redirection is allowed only if both original and target documents say same information.
    3. The document may contain link to a page describing what technologies may be unsupported on user's device, what their better support may cause, and what advantage may be gained from it. This information must not imply a need of using certain type or brand of target device. If this document contains links to products, alternatives must be offered.
  11. External Data:
    1. Defining styles in a <style> tag, using the style atribute, and writing script's code within the document are forbidden. A <style> tag may contain only @import rules.
  12. Extensions:
    1. The document and its extensions must be prepared for inactivity or inaccessibility of any device's or document's supplement (disabled or inaccessible images, disabled scripts, styles and/or cookies, inactive plug-in etc.). Unsupported extension must not reduce the content accessibility in any way.
    2. While using an extension, any (informational valuable) data must not be imported or generated, if they arent't accessible directly from the document at once.
    3. If an application is made by joining content, styles and scripts, any document's presentation requiring the script activity must not be used when the script is not active and fully supported, if it may diminish document usability. This means, if the author defines a special stylesheet requiring script's activity, the stylesheet must be added to the document by this script, after its future functionality is checked up. If the document should contain elements making no sense without script's activity (navigation buttons, dynamic menus), these elements must originate from the script (adding new elements or modifying present elements).
    4. A script (or other document's extension) must not reduce the usability of the target device in any way. Especially, it must not disable browser's buttons or menus, resizing or closing document's window, user's fonts, colors or styles, etc.
    5. Without user's explicit request, a script (or other extension) must not change parameters of the user interface. Any action, like resizing or closing a window, quitting the application, saving a bookmark etc., are allowed only as the result of user's action, and only if the user is warned of effects of this action.
  13. Extension Support:
    1. If any script operation or style property (needful for running of the extension) is not supported by the target device, the author may deactivate whole extension, or reduce its functionality. However, it must not diminish the usability of the document.
    2. Wrong implementations of functions or properties, or runtime error of a device are out of scope author's arrangement. However, well known browsers errors may be treated or bypassed by additional constructions. They must not bound mistake-free devices.
  14. Colors:
    1. Color combinations, embarrassing document usability for color-blind users (daltonism, chromatopsy disease etc.), are forbidden.
    2. Text background must not be violated by other color boundary (border, background or content of other element, document border etc.) at least 1/10 of font size vertically and 1/2 of font size horizontally from the text.
    3. Color brightness means the percentage of gray originated from the color (0 is black, 100 % is white). Only these colors may make foreground-background combinations, whose grayscale representations percentage differs by 50 or more.
    4. White or black text must be displayed on background other from black or white. Color indication of links may be kept, yet they must follow comfortable brightness difference from the background.
    5. The text and background rules are also valid for informational valuable text in images and other objects.
  15. Text:
    1. The space between adjacent text blocks must be vertically higher than spaces between lines of text of both blocks. Horizontal space between text blocks must be at least as twice wider as the word-spacing.
    2. The last value of font-family must be one of keywords serif, sans-serif, monospace, cursive, or fantasy.
    3. In continuous structured text making the message of the document, each heading level must differentiate from other levels and its form must reflect the structural superiority and inferiority.
  16. Avowal:
    1. If the author avows honouring Dogma W4, the code of the document must contain string "Dogma W4" followed by link to this Proclamation & Principles. Graphical symbols W4D may be used as well, e. g.: