The Dogma W4 - details and explanation

Ad 7. The links and active elements in the document

All links and other active elements used in web documents must clearly identify the nature of their destinations or results they will cause.

Details: Regular user's actions must have regular results.

If user's action causes any change outside the document (opening a new window, closing a current one, commencing a file download), the user must be warned in advance. The link must too be provided with information about type, size and ways of processing of the target file if it points to the file, which cannot be presented in the browser. Interaction with form elements (selecting from list, checking a box etc.) must not cause a jump to a new document.

Details: Every link must clearly identify its target.

Links like "here", "click here" etc. are forbidden. Captions of submit buttons in forms must as well clearly identify action, which takes place after their activation. Text like "send", "reset", "search" are appropriate, whereas uncertain or "funny" captions are unacceptable.

Details: The links with same captions must have the same target.

When the two links in the document have the same content, their target must be equivalent. If the links are made of icons, glyphs, symbols, or action names are the same for more items of the list, the target identification may differ in the title attribute. I.e.:

Details: Links within document must point to easily identifiable and irreplaceable target.

Target of "link into the document" should be identifiable in surrounding content and should correspond to the link's text (see also The navigation - links into the document). Links to the automatically numbered lists (i.e. <ol>) must not contain value, which may be generated for the target item (i.e. "see 9.2.1").

All links must remain underlined, except when link underlining is disabled by the user.

Details: hypertext links are displayed as underlined text with adequately different color from surrounding text.

Author must not in any way prescribe such presentation of links that may cause their substitution with surrounding text or other document elements. Especially he must not prohibit their underlining and/or displaying in color, which is not different enough from the surrounding text. He must not set any text, which is not link, to be underlined or in color used for displaying links. Author must not deny user to use whichever style of links presentation he wants.

Author must not change the style of cursor over the links. For example in HTML/XHTML he must not set the <a> element to have a CSS cursor property.

Visual reformatting of a document may be caused only by activating an element.

Links (and other elements) must be programmed the way, that interaction with the user, causing the change in their visage does not cause reformatting of the document. I.e. dynamical effects (:hover, onmouseover) may change a background color and text decorations, style of background or visibility (visibility) of the element. However element's dimensions, font size and weight, or even the way of rendering (display) must not be changed - these changes cause reformatting of surrounding elements and possibly whole document, and may therefore be proceeded only by user's request (activating a link, pressing a key etc.).