The Catalogue consists of the themes, nodes having following types: 
- Any File (A) - arbitrary file, which contents cannot be edited, but there is possibility to download or upload it. 
- HTML (H) - HTML page, can be edit from browser. 
- Text (T) - a text file, can be edit from browser. 
- DB Table (D) - database (DB) table which contents we can search through the Query tool; table is edited by records. 
- List (L) - list, analogue of a file directory. 
- URL Link (U) - a link (reference) to a Web resource. 
- Reply (R) - the response, the text from several words. 
- Item (I) - a final element of the list.