Without conventions, every programmer in an organization does their own thing.
Problems arise whenever someone else has to look at the code.
For example, suppose the same module is written by two different programmers. The code of one programmer takes 1 hour to understand and verify, while the same code by the other programmer takes 1 day. The primary factor that affects the readability of code is the presence of naming conventions. If strict naming conventions are followed, simply looking at a symbol quickly tells the reader what the symbol is, where it is defined, and whether it is a variable, constant, macro, function, type, or some other declaration. Such conventions must be posted, just as a legend must appear on a design diagram, so that any reader of the code knows the conventions.