IMHO code guidelines are there to avoid wasting time on trivialities. Why would something which is already settled by the guidelines even crop up code reviews,

IMHO code guidelines are there to avoid wasting time on trivialities. Why would something which is already settled by the guidelines even crop up code reviews, except for the first few commits from a junior developer? Lots of style choices are more or less arbitrary. PascalCase or camelCase? Big endiand or little endian? Comments and identifiers in english or french? You cant just "demand competence" because neither is clearly superior. But consistency is clearly superior to everyone doing it their own way. So you make a decision, write it down in a guide, and the question will not take up any more time and attention. But yeah, a guideline which legislates obsolete code constructs is obviously bad. Clearly something is deeply wrong in the culture of the team if the guideline is 20 years out of data and no one care about updating it - while at the same wastes a lot of resources on pointing out the issues in code reviews! But that problem is not with guidelines per se. Using an obsolete compiler will probably also give you problems.