On Feb 27, 2015, at 10:28 AM, Jeff Morriss <jeff.morriss.ws@xxxxxxxxx> wrote:
> My opinion (which I've voiced on this list many times over the past ~10 years) is that such fields SHOULD be dissected. Even better they should have an Expert Info if they are supposed to be 0 and aren't (Guy had suggested on a bug or somewhere that we should have an API with a name that includes "mbz"--for Must Be Zero--which would add the Expert Info automatically).
It was in the thread that started here:
https://www.wireshark.org/lists/wireshark-dev/201402/msg00131.html
and I suggested both proto_tree_add_spare() (for fields that are spare and *not* required to be zero) and proto_tree_add_mbz() (for fields that *are* required to be zero) in
https://www.wireshark.org/lists/wireshark-dev/201402/msg00135.html
Neither of those take an hf_ value as an argument, so they don't clutter the list of filterable fields with a bunch of individual values for each set of spare bits; to look for "must be zero but isn't", you'd look for the expert info.
