# Strange setting in FormatValues[MakeExpression]

My sytem is: 8.0 for Mac OS X x86 (64-bit) (October 5, 2011)

When I start Mathematica and call

FormatValues[MakeExpression]


I get the following output:

The message says:

Where does it come from and what is a RefBox?

-
Why would you be interested in FormatValues[MakeExpression]? –  Sjoerd C. de Vries May 28 '12 at 13:58
@Sjoerd To make some output "prettier", I use FormatValues and I inspect them to see if everything is correct. BTW it seems, that the entry above does no harm, but if I spot an error/warning I´m curious where it comes from. –  Peter Breitfeld May 28 '12 at 14:05
I see, but MakeExpression isn't a function that you want to pretty-print, is it? I can imagine that for D and Integrate, but not for such a low-level function as MakeExpression. –  Sjoerd C. de Vries May 28 '12 at 14:10
@Sjoerd I want e.g. to print Abs[<stuff>] as |<stuff>| enclosed in \[LeftBracketingBar] and \[RightBraketinbar] in StandardForm, and I use MakeBoxes and MakeExpression for this. –  Peter Breitfeld May 28 '12 at 14:21
But in that case you would need to look at FormatValues[Abs], wouldn't you? –  Sjoerd C. de Vries May 28 '12 at 14:29

The reason that MakeExpression has any FormatValues at all is because there's one defined in GetFEKernelInit.tr for some experimental functionality (which we probably ought to clean up in a future release). The fact that it's experimental also led to our not fully implementing the error-handling cases of typesetting, which is the source cause of the pink box.
You could just ignore the pink box. Or, if it's really distracting, you can simply request the results in InputForm. E.g.,
FormatValues[MakeExpression] // InputForm