Add a scary, all-caps warning to the docs for RejectParserCacheValue

Follows I660679a4.

Change-Id: I65bde4f0f6939c9a1e3e06dcbdbf9856e4416df9

diff --git a/docs/hooks.txt b/docs/hooks.txt
index 5480a25..bcdfa40 100644 (file)
--- a/docs/hooks.txt
+++ b/docs/hooks.txt
@@ -2410,7 +2410,9 @@ such as Special:MyPage and Special:MyTalk.
 &$redirectParams: An array of parameters preserved by redirecting special pages.
 
 'RejectParserCacheValue': Return false to reject an otherwise usable
-cached value from the Parser cache.
+cached value from the Parser cache. NOTE: CARELESS USE OF THIS HOOK CAN
+HAVE CATASTROPHIC CONSEQUENCES FOR HIGH-TRAFFIC INSTALLATIONS. USE WITH
+EXTREME CARE.
 $parserOutput: ParserOutput value.
 $wikiPage: WikiPage object.
 $parserOptions: ParserOptions object.