No, that clashes with variable declarations. Sure, you could have a naming scheme that doesn't have that issue, but that doesn't help with library code.

Pretty much.

Here's some declarations from an ancient UNIX (remember, UNIX(R) is a registered trademark of "The Open Group") ctags file to help show how that type of scheme works:

  ISDOT rm.c    /^#define ISDOT(a)      ((a)[0] == '.' && (!(a)[1] || (a)/
  Mrm   rm.c    /^main(argc, argv)$/
  PASS  rm.c    /^#define       PASS(byte) {                                    \\$/
  check rm.c    /^check(path, name, sp)$/
  checkdot      rm.c    /^checkdot(argv)$/
  rm_file       rm.c    /^rm_file(argv)$/
  rm_overwrite  rm.c    /^rm_overwrite(file, sbp)$/
  rm_tree       rm.c    /^rm_tree(argv)$/
  usage rm.c    /^usage()$/