I question the need of rule 10.6

[jbezem]

The intention of my code sample never has been to show MISRA-compliant code, just to show one of the many bizarre properties of the C language standard. Using a 'U' suffix in my sample helps in that the behaviour of the code becomes identical in both cases. I just wanted to make a case in favour of the use of the 'U' suffix for unsigned constants, nothing more, but nothing less.
Failing to observe Rule 10.6 in my sample leads to bugs, increases misunderstandings and confusion, and affected the safety of my system. That my code is additionally violating a plethora of other MISRA rules is IMHO not the point.
If you don't like the use of suffixes on constants, fine with me. If casting every constant to the appropriate type is more to your liking, you'll even get better results, since the type information is more accurate. I take the freedom to consider that less readable than suffixes, but that's my personal opinion.

people mixing signed integers and hexadecimal notation are asking for trouble

The reason I wrote my blog entry was to alert people to the fact that a hexadecimal number and a decimal number of the same value may be treated differently depending on the actual value and the types applicable to those values. Many developers using constants cannot even tell you the actual type of a constant they use, and they should care, in order to avoid mixing signed numbers and hexadecimal notation inadvertently.

And yes, you are right, my last example has got nothing to do with 'U', but with 'L'.

I consider MISRA a tool to help developers, not a language specification for a subset of C. But again, that's just my opinion.

Regards,

Johan