patch 7.4.1658
Problem:    A plugin does not know when VimEnter autocommands were already
            triggered.
Solution:   Add the v:vim_did_enter variable.
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 642f0ad..e174481 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -1762,6 +1762,10 @@
 		version 5.0 and 5.1 may have a patch 123, but these are
 		completely different.
 
+				*v:vim_did_enter* *vim_did_enter-variable*
+v:vim_did_enter	Zero until most of startup is done.  It is set to one just
+		before |VimEnter| autocommands are triggered.
+
 					*v:warningmsg* *warningmsg-variable*
 v:warningmsg	Last given warning message.  It's allowed to set this variable.