Accessibility
The objective of the ONCE Foundation is that everybody, regardless of whether they have a disability, their age or whether they access the web using unconventional technologies, can navigate the pages of this web site without encountering access difficulties. 
To such end, the development of the portal has been based on fulfilment of the Web Content Accessibility Criteria 1.0 established by the W3C (World Wide Web Consortium).
Some of the functions implemented in the web to facilitate access to all the contents are:
- The visual characteristics of the portal (type of letter, colour of font and background, etc) are defined by means of the styles sheets so the user can adjust the text to his preferences.
- The sizes of the fonts have been defined with relative units so that the size of the font can be increased or decreased from the navigator options.
- If a user accesses the portal with a navigator that does not support styles sheets, this will not cause a problem, as all the contents can be equally accessed with the CSS deactivated.
- The pages have a clear structure both for the user who can see all the content, and for the user who reads the information with a screen reader, users who deactivate the styles sheets etc. Under this objective the section headings, the lists and all the elements that help the general understanding of the web site have been defined using the HTML code.
- The HTML code and CSS used are adjusted to the formal grammars to guarantee the correct visualisation of the contents in different navigators.
