If a document is edited simultaneously by several authors, or if different variants are to be managed in parallel, you may create two or more parallel version branches of the original document, each having its own ‘current version’. A new version branch is again a document under version control that starts out from an arbitrary version of the original document. You may also create branches of branches.
•      
Select 
  Change  
  Branch  
from the action menu of a document under version control. 
• In the version history of the ‘Branch’ form, select the version from which the new branch is to originate by clicking its radio button in the ‘Id’ column. Enter a name for the new version branch.
The first version of the new branch document is a copy of 
the root version of the original document in the same folder. The state is also 
copied. The version number is formed by appending 
next-branch-number.1. The latter may be changed using 
  Change  
  Version 
Info . 
Note: Copying documents under version control means branching, i.e. a new version branch of the document is automatically generated in the clipboard.
BSCW does not provide any specific support to ‘re-unite’ several version branches that have been modified in parallel. Therefore it is important to have telling change descriptions and to agree beforehand on a document editing and versioning strategy in order to facilitate the process of bringing the different branches together into a single consolidated document.
Note: When 
revising a branch version, you cannot store the new branch version as a main 
version, i.e. you cannot increase a branch version number to a main version 
number.    
An example: Let’s assume that you have generated a 
new branch 0.1.0.1 starting from version 0.1. You edit the underlying file 
of the branch version and store it as new branch versions, 
increasing the branch version number to 0.1.0.2 and 0.1.0.3. When you 
now want to save a new branch version as a main version, you cannot simply 
increase 0.1.0.3 to, say, 1.0 for reasons of version security. Instead, you 
have to enter 0.1.0.4 as branch version number and revise the main version by 
uploading the file underlying the 0.1.0.4 branch version as the new 1.0 main 
version.