### Branching versions

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.