I concede that I am not one of the people that catch on quickly to some rules no matter how many times I read them and that I can be very dense to explanations provided by others. Another challenge is that during my twenty years of being in the USN following instructions per documents was done to the letter. Failing to follow the instructions worst result would to the loss of a ship, submarine, or aircraft with the entire crew the least bad result is that you got hurt, for example a cut finger requiring a band-aid with a stitch or two. Hopefully, I'll be able understand somebody's explanation the first go round.
On the Heavy Weapons Ammunition Table pp. 345-346 of BT TechManual PDF CAT 35002 2007-2013 The Topps Company, Inc. Corrected Third Printing Published by Catalyst Game Lab are the specifications for Incendiary (LRM) warheads.
The first footnote character is an asterisk (*) which I understand to mean that the specifications are identical for the LRM launcher using Incendiary warheads.
The second footnote is "‡Incendiary LRM capability may be combined with one other LRM special munition type (including standard, but excepting Thunder); in such cases the heat, damage, range, and ammo capacity/weight statistics of the other missile type apply, but rack size is treated as 5 tubes smaller."
My impression from the second note is that when combining an Incendiary in another warhead type the specification for both warheads are applied on a successful To-Hit Roll.
Further because of the combined warhead the LRM launcher is treated as one 5 tubes smaller.
Would a LRM 5 launcher be considered a LRM 1 or LRM 0?