There is NOW a warning horn on the 30 second replacement period. The substitute must report before the end of the 30 seconds, not before the 20 second warning horn though.
This was an NFHS rule change before the 2003-04 season.
2-12-5
. . . Sound a warning signal at 20 seconds of the 30 seconds (maximum) permitted for replacing a disqualified or injured player, or for a player directed to leave the game.
I'd say you're buying.
I'll also add that the DQ replacement was a POE that year. POE #5 does a great job detailing the finer points of handling that aspect of the game. It is quite long and there is NO WAY that I am going to type it all out. Perhaps someone else has an electronic copy and could cut and paste it.
[Edited by Nevadaref on Feb 6th, 2005 at 06:59 AM]