HTML is a mark-up language used to create websites, and is independent of platforms.
"HTML is not a programming language, since HTML does not allow to, say, control a robot, set a variable or programme a game." (Quelle)
The display of invalid or incorrect documents depends on the software reading them (browser, roboter, screenreader, etc; see above). However, the display will vary greatly depending on the software, and this can lead to errors, often without the knowledge of the website manager, since it is impossible to test the website against all updates of all the software.
Non validated HTML source text can cause high costs, especially if it causes the software to look for an error or if the functionality and therefore the user experience is impacted.
Further information:
The validity of the HTML source text can be checked with a so-called 'validator'.
Examples:
Further information
http://blog.antikoerperchen.de/beitrag/28/validierung-wozu-warum-valider-html-code-wichtig-ist.html
Acronyms:
HTML: HyperText Markup Language
The majority of the pages are valid, but not all.
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Separating design and structure of the website carries great advantages. The sharper the distinction, the more independent the two areas are. A lack of such a distinction is also called a "spaghetti mark-up" or a "tag-soup" (from the term "HTML tag").
Nowadays it is easy to save colours, type fonts, design images and to a large extent even the layout of the website in CSS files (CSS = Cascading Style Sheet).
Further information:
http://www.style-sheets.de/guide/grundlagen/warum_css
http://www.vorsprungdurchwebstandards.de/theory/retro-coding/
Hint for IT technicians: "Code" does not refer to javascript, but to HTML source.
The tested website contains a small amount of spaghetti mark-up in CSS format.
A table based layout carries many disadvantages if compared to a purely CSS layout. A CSS layout improves both accessibility and performance.
Further information:
A detailed article by Douglas Bowman can be found onhttp://www.stopdesign.com/articles/throwing_tables/.
Hint for webmasters: Be sure that when embedding third party content, e.g. with iFrame, there are no layout tables included.
On the tested website there are many tables, which most probably are also used for the layout.
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A potential hint has been identified.
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A potential hint has been identified.
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Alternative text is displayed if an image cannot be downloaded or if the mouse pointer is moved over the image*. The alternative text is on one hand important for visually impaired visitors, using an audio tool to read the content of the website and the alternative text of images.
On the other hand, alternative text can also be recognised by search engines. Alternative text needs to be phrased in a meaningful manner, though it should not be a detailed description of the image.
Further information:
http://www.bjoernsworld.de/html/alt-text.html
http://webdesign.crissov.de/alt-Text#Start
* Internet Explorer shows alternative text as a tooltip if the mouse pointer is rested on the image. This is not prohibited but it can annoy page authors. It does also indicate that the alt-attribute refers to this tooltip, which is wrong. Should you want to add a descriptive tooltip to your images, make use of the attribute "title".
Quelle: http://de.selfhtml.org/html/grafiken/einbinden.htm#referenz
The tested website contains alternative text for images, though the length of the alternative text is for one image at least outside the range between 8 and 80 characters. Alternative text which has correctly been recorded as empty will not return a negative result.
Using the ideal number of keywords can contribute to the searchability of a website. However, search engines may class it as "keyword spam" if too many keywords are used.
The number of keywords contained in the tested website is not optimal.
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A potential hint has been identified.
This test result is available for registered users and Premium Members.
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A potential hint has been identified.
This test result is available for registered users and Premium Members.
More than two thirds of the test results will be available to you once registration has been successfully completed.
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A potential hint has been identified.