Documents as Online Documentation 
Definition
Online documentation for a BW object is a document that has been generated for a particular metadata object. This document can contain a text written by the user.
Use
Online documentation is usually displayed as F1 Help for the object to which it is assigned.
Online documentation is displayed in the following situations:
Display Documentation pushbutton. The F1 Help is displayed in the Web browser.
Display Documentation pushbutton to display the F1 Help in the Web browser. Structure
The online documentation for a BW object is made up of the following parts:

In a generated version of the online documentation, you can use the search function (see

To include SAP Content documentation in the online documentation generated for metadata objects, it must be installed in plain html http format for static help and using a Web server. The Content documentation can then be read by the Web server from any frontend platform using the http protocol, and displayed in a Web browser.
You can find additional information about maintaining setting variants for online help (transaction SR13) in the Business Information Warehouse Implementation Guide (IMG), under the node General BW Settings ® Settings for Displaying SAP Content Documentation.

For a characteristic this would be, for example:
Under Additional Objects, for example:
The links are generated dynamically from the metadata repository and are, therefore, always up-to-date, even if the data model is changed.