Okay so op asked me what my systems forms teach so here's that answer from me.
Each form in American kenpo has a specific theme and each form signposts on to the next one so they're not all just a bunch of randomly thrown together moves there's always some connection to the others.
Short form 1 teaches you how to retreat from your opponent and use the basic blocks, the theme of that form is rotation for the rotation of your hips used when blocking.
Long form 1 is the same base as short 1 but after each block a reverse punch is thrown so that adds in counter attacks and the main theme is back up mass which is your forward bow stance on the punch.
Short form 2 teaches you to step into an attack and how to have a different timing on your movement and the need for checks due to the fact your stepping into the attack. This is also the first form to go on a different angle base. The first 2 forms worked on a plus symbol. (If you looked at me doing th form from above you'd see moving in a plus shape going to the basic clock angles of 6,3,9 and 12 o clock. But this form you move on the X angle and introduces a change in height by dropping under an attack.
Long form 2 shows you to use your front hand as an attack and how to move to different angles. It also teaches something new by being the first form to punch before you block and introduces elbows.
Short form 3 is a new theme all together, the previous were all movement all of them from now on are self defence technique forms where the form is made uo of techniques from the syllabus but all put together and have to use transitions to do them at different angles. This forms them is dead attacks (grabs)
Long form 3 adds to this by doing the techniques on both sides (short form 3 you only did it one side) this teaches you to adapt to both sides of the technique and it a,so teaches isolation of wrist grab escapes. This forms theme is semi live attacks.
Long form 4s theme is live attacks (punches and kicks) and it teaches you to work on different height levels by dropping to a knee simulating you've been knocked down.
Long forms 5 theme is takedown techniques and being struck from an unnatural start point when your not expecting it.
I don't have as much info on the last 2 as those are newer forms for me. But now I'm no form master, it's not my area of expertise but I've been able to tell you all of this just off the top of my head without having to read anything, not because I was specifically trained at one point but because over all my years I was given these little bits of infortmation as I go