All source code files should contain comments (near the start of the file) describing the creation and modification history. This is quite important in the MIRIAD development environment, where programs are spread across many computers and programmers are separated by many miles.
Below are typical history comments (taken from the ``key'' routines, subroutine key.for):
c************************************************************************ c The key routines provide keyword-oriented access to the command line. c c History: c rjs 6jun87 Original version. c bs 7oct88 Converted it to use iargc and getarg. Added -f flag. c rjs 8sep89 Improved documentation. c nebk 10sep89 Added mkeyr. I think rjs will not like it (Too right!). c rjs 19oct89 Major rewrite to handle @ files. c rjs 15nov89 Added keyf routine, and did the rework needed to support c this. Added mkeyf. Modified mkeyr. c pjt 26mar90 Added mkeya. like mkeyr (again, bobs will not like this) c pjt 10apr90 some more verbose bug calls. c rjs 23apr90 Made pjt's last changes into standard FORTRAN (so the c Cray will accept it). c pjt 10may90 Make it remember the programname in keyini (se key.h) c for bug calls - introduced progname c rjs 22oct90 Check for buffer overflow in keyini. c pjt 21jan90 Added mkeyi, variable index is now idx, exp is expd c************************************************************************