DP/FLEX or DP/DEFO History of Rule

[marvin]

When was this rule first put in place?

This has come up in a discussion in this thread and rather than lead that thread farther off-topic I am starting a new thread.

I believe that 2004 is correct for NFHS. See this article on officiating.com, but in ASA the rule was in effect prior to that. It was DP/DEFO before the terminology was changed to DP/FLEX.

I did find this pdf file that has the DP/DEFO going into effect for ISF in 2001/2002.

The first use of DP/DEFO I remember was around 1989/1990 in ASA. My daughter was playing 14U at the time and I remember it because it came up in a tournament championship game. (although it may have been a year or two later when she was in 16U).

Do any of you have old rule books or any reference for when this rule went into effect first? What rule set adopted it first? I am just curious, thanks for your help.

Edit: I found a 1998 ASA rule book with the DP/Defo rule. Anyone know the first year for this rule?