I have mentioned it before, but my description of old FORTRAN idioms, like COMMON blocks and the use of ARRAY(1) instead of ARRAY(*) and the like, is nearing completion. You can find the result at https://github.com/arjenmarkus/old-programming-idioms/tree/main/doc, in the hope it is useful. And otherwise it was fun anyway to write it up.
I will not be making any more changes until I am back from my holiday (beginning of august), but I do appreciate comments, additions, corrections and other suggestions for improvement.
@Arjen
Excellent work. For those of us who have had the unfortunate task of trying to teach younger people about the differences in what I like to call Jurassic FORTRAN and Modern Fortran, having a Rosetta stone is a big help. One omission I would like to point out though is SENSE SWITCH . Just kidding but you would be surprised how often it appears in old 1960 era NASA reports that contain full code listings.
Edit.
Also, if you can find a copy in a library somewhere, I would recommend you look at Fredrick Stuart’s " Fortran Programming" book circa 1970 (my first Fortran book). It has some nice fold out tables on the capabilities of various compilers and hardware from that period and also does a good job of covering what was I guess the unofficial standard at the time sometimes referred to as Fortran IV.
Perhaps you will consider working Fortran-lang folks to create a “Rosetta Stone”, as mentioned by @rwmsu upthread, and strive toward a link to it under Learn — Fortran Programming Language?
It can then be a Community-driven effort where other contributors can submit PRs for additional idioms and other idiosyncrasies to keep in mind when it comes to working with or reviewing legacy FORTRAN code?
Likely more suitable for short intermittent use, there is a digitized copy on archive.org of Wiley’s edition by 1969 (requires their free libary card; pending availability, the book can borrowed in slots of an hour each). Else, entry worldcat.org.
to write it up.
. Just kidding but you would be surprised how often it appears in old 1960 era NASA reports that contain full code listings.