+(defcustom hi-lock-file-patterns-policy 'ask
+ "Specify when hi-lock should use patterns found in file.
+If `ask', prompt when patterns found in buffer; if bound to a function,
+use patterns when function returns t (function is called with patterns
+as first argument); if nil or `never' or anything else, don't use file
+patterns."
+ :type '(choice (const :tag "Do not use file patterns" never)
+ (const :tag "Ask about file patterns" ask)
+ (function :tag "Function to check file patterns"))
+ :group 'hi-lock
+ :version "22.1")
+
+;; It can have a function value.
+(put 'hi-lock-file-patterns-policy 'risky-local-variable t)