##### 16.9.2.3 Defining revision information

Some VCS reports revisions number from which it is possible to deduce the related branches. This is the case in CVS for example where a revision number for a branch uses as prefix the branch point revision number. For such VCS it is possible to specify two regular expressions:

`parent_revision`
  Parse the revision number and report as first match the parent revision.

                  <parent_revision regexp="..." />

  For CVS on 1.2.4.5 it must match 1.2.

`branch_root_revision`
  Parse the revision number and report as first match the branch root revision.

                  <branch_root_revision regexp="..." />

  For CVS on 1.2.4.5 it must match 1.2.4.