user8201: A well-answered question here: FIDE Laws of Chess pre-2017 asks for locations of historical sets of FIDE Laws. I am asking for something which partially builds on that.
Is there a timeline of "key" historical changes to rules (FIDE, USCF and earlier) & the WFCC Codex of Chess Problem Conventions, please? It's not going to be perfect initially or ever, but something which can grow.
Having such an artifact would allow us to assign a historical context to those chess compositions that riff on specific rules and conventions, for example: Dummy Pawn, Bosma theme, Dead Reckoning, Retro Strategy & Partial Retro-Analysis. This would be a general foundation for specific timelines listing relevant compositions themselves, e.g. the one at When (if ever) was it a rule that pawn promotion was optional?

user4418: 
Is there a timeline of "key" historical changes to rules (FIDE, USCF
and earlier)

Not so far although former FIDE rules commission member, Stewart Reuben, recently said:

To make it clear. I am writing a book, together with my co-authors Alex McFarlane and Sean Press. It is called A History of the Laws of Chess. Alex is dealing with the first section, from about 600 AD to the 15th century with the old rules. Sean is dealing with the introduction of the augmented powers of the queen, bishop and pawn 15th century to the formation of FIDE. I am dealing with the Laws since FIDE was formed IN 1924. That section is more-or-less completed.


8201: <p>A well-answered question here: <a href="https://chess.stackexchange.com/questions/26807/fide-laws-of-chess-pre-2017">FIDE Laws of Chess pre-2017</a> asks for locations of historical sets of FIDE Laws. I am asking for something which partially builds on that.</p>
<p>Is there a timeline of &quot;key&quot; historical changes to rules (FIDE, USCF and earlier) &amp; the WFCC Codex of Chess Problem Conventions, please? It's not going to be perfect initially or ever, but something which can grow.</p>
<p>Having such an artifact would allow us to assign a historical context to those chess compositions that riff on specific rules and conventions, for example: Dummy Pawn, Bosma theme, Dead Reckoning, Retro Strategy &amp; Partial Retro-Analysis. This would be a general foundation for specific timelines listing relevant compositions themselves, e.g. the one at <a href="https://chess.stackexchange.com/questions/21212/when-if-ever-was-it-a-rule-that-pawn-promotion-was-optional">When (if ever) was it a rule that pawn promotion was optional?</a></p>
 4418: <blockquote>
<p>Is there a timeline of &quot;key&quot; historical changes to rules (FIDE, USCF
and earlier)</p>
</blockquote>
<p>Not so far although former FIDE rules commission member, Stewart Reuben, <a href="https://www.ecforum.org.uk/viewtopic.php?f=2&amp;t=9330&amp;p=245229&amp;hilit=fide%20history#p245229" rel="nofollow noreferrer">recently said</a>:</p>
<blockquote>
<p>To make it clear. I am writing a book, together with my co-authors Alex McFarlane and Sean Press. It is called A History of the Laws of Chess. Alex is dealing with the first section, from about 600 AD to the 15th century with the old rules. Sean is dealing with the introduction of the augmented powers of the queen, bishop and pawn 15th century to the formation of FIDE. I am dealing with the Laws since FIDE was formed IN 1924. That section is more-or-less completed.</p>
</blockquote>
