The Web site of is designed for the following browsers:

You have to switch on the following options of the browser you use:

  • CSS
    Necessary for the complete formatting and design of the page.
  • JavaScript
    Allows additional interactivity in the navigation elements.

It is possible that you have to switch them on from the "Preferences" menu of the browser you use.

Accessibility of

The above stated browsers support loading of certain pages by pressing a combination of a functional key and an access key defined on the Web site.

For the Web site are defined the following access keys:

Main Content:

Windows users: ALT+"s";

Macintosh Control+"s".


Windows users: ALT+"0".

Macintosh Control+"0".

If you have any questions or comments, regarding the accessibility of, you can write to us at the following address:

  • Most of the links on the Web site have a "Title" attribute, describing in detail a certain link.
  • Links, which open in a new window, are indicated as such in their description with the note "in a new window".


  • All illustrations on have an "Alternate text" attribute, describing the illustration with a text.

Visual Design

The Web site uses CSS for visual layout and appearance:

  • You can set the font size of the pages according to your needs. In Internet Explorer you can change this setting from the menu "View > Text Size". In Mozilla Firefox you can change this setting from the menu "View > Text Size > Increase/Decrease". In Safari you can change this setting from the menu "View > Make text bigger/smaller".
  • For browsers that do not support Cascading Style Sheets (CSS), the content of each page of will be accessible and comprehensible.

Abbreviations and Acronyms

  • The abbreviations and acronyms, used in the content of the Web site, , have a "Title" attribute, displaying the whole word or phrase.


In order to correctly reproduce the whole information from the Web site of, it is possible that you might need the installation of additional software. The reference notes below will help you download and install the programs you need:

Help from Us

If you need additional advice for the use of the Web site, please contact our system administrator at the following address:

You need to upgrade your Flash Player

ContactsAll Contacts

Contact with Communications Department

(+359 2) 812 24 88

Business Park Sofia, Mladost 4, Sofia 1766, building 2A