Index: app/models/build.rb
===================================================================
--- app/models/build.rb	(revision 490)
+++ app/models/build.rb	(working copy)
@@ -143,6 +143,8 @@
     old_rails_env = ENV['RAILS_ENV']
     ENV['RAILS_ENV'] = nil
 
+    # set OS variable CC_BUILD_LABEL so that custom build tasks know it
+    ENV['CC_BUILD_LABEL'] = self.label
     # set OS variable CC_BUILD_ARTIFACTS so that custom build tasks know where to redirect their products
     ENV['CC_BUILD_ARTIFACTS'] = self.artifacts_directory
     # CC_RAKE_TASK communicates to cc:build which task to build (if self.rake_task is not set, cc:build will try to be
Index: app/views/documentation/manual.red
===================================================================
--- app/views/documentation/manual.red	(revision 490)
+++ app/views/documentation/manual.red	(working copy)
@@ -168,6 +168,8 @@
 
 The build page includes links to every file or subdirectory found in the build artifacts directory.
 
+Another OS variable, CC_BUILD_LABEL, may also be useful. It contains build label, a string like 
+'6272.1'.
 
 h1. Build monitoring