For decades(!) I used CamelCase identifiers, with a convention of using an upper case first letter for constants/types/functions and a lower case first letter f

For decades(!) I used CamelCase identifiers, with a convention of using an upper case first letter for constants/types/functions and a lower case first letter for variables. e.g. MyType myType; I'm not quite sure what made me switch, but nowadays I used lower case and underscores for all identifiers other than constants, and use a "_t" suffix to distinguish types. e.g. color_t color; string_list_t list; I think it's certainly easier on the eyes and more readable. At the end of the day though it's personal preference, unless you're working on an existing code base where you should adopt the naming and formatting conventions of the code base.