Some clarifications to the main doc.

Signed-off-by: Yann Dirson <ydirson@altern.org>

diff --git a/Documentation/stg.txt b/Documentation/stg.txt
index 60a6f9cd8b4b8a1f636e03b03678dc56c7915aca..7d923562e1781fe8ffc39dfeb79fad0e3f01ae37 100644 (file)
--- a/Documentation/stg.txt
+++ b/Documentation/stg.txt
@@ -21,19 +21,33 @@ GIT. These operations are performed using GIT commands and the patches
 are stored as GIT commit objects, allowing easy merging of the StGIT
 patches into other repositories using standard GIT functionality.
 
+An StGIT stack is a GIT branch with additional information to help
+making changes to individual patches you already committed, rather
+than making changes by adding new commits.  It is thus a
+non-forwarding, or rewinding branch: the old head of the branch is
+often not reachable as one of the new head's ancestors.
+
 Typical uses of StGIT include:
 
 Tracking branch::
-       Maintaining modifications against a remote branch, possibly
-       with the intent of sending some patches upstream.  StGIT
-       assists in preparing and cleaning up patches until they are
-       acceptable upstream, as well as maintaining local patches not
-       meant to be sent upstream.
+       Tracking changes from a remote branch, while maintaining local
+       modifications against that branch, possibly with the intent of
+       sending some patches upstream.  StGIT assists in preparing and
+       cleaning up patches until they are acceptable upstream, as
+       well as maintaining local patches not meant to be sent
+       upstream.
++
+In such a setup, typically all commits on your branch are StGIT
+patches; the stack base is the branch point where your changes "fork"
+off their parent branch.
 
 Development branch::
        Preparing and testing your commits before publishing them,
        separating your features from unrelated bugfixes collected
        while developping.
++
+In such a setup, not all commits on your branch need to be StGIT
+patches; there may be regular GIT commits below your stack base.
 
 OPTIONS
 -------