Each note is stored in its own directory, subdirectories actually create a tree. All other subdirectory are sub-notes. For example, this reference is organized this way: Attach:tree.txt

Each directory and the root of tree contains a file ''__page.opt'', which stores the settings for individual notes (tag, page type, etc.). Also, in subdirectories there are files''__page.text'' - the contents of the notes (the format of this file depends on the type of page) and, possibly, ''__icon .*'' - an icon in any graphic format 16 × 16 pixels.

Each directory contains a subdirectory ''__attach'', which contains attached files, so to attach a file to a note, you just copy it the directory ''__attach''.

Due to this structure you may open each branch as a separate tree, but at the same time you must remember, that the root element of the tree itself does not contain a note and is only used as a container for sub-pages.

Files and directories created by OutWiker, begin with two underscores.