I'm trying to figure out what happens when a UG routs through a friendly unit. The rules seem... complicated. Here's what I've worked out:

The main rule is 9.7B6 (p. 166):

QuoteIf they meet friends they pass through them as per the rules for passing through friends (8.3D (really 9.3H)), causing KaB tests where appropriate.

Rule 9.3H5 (p. 110) reads:

Quote5. The following passing through moves are allowed without causing KaB tests.
5.1 Infantry SuGs may pass through any friendly TuG or SuG in any direction.
5.2 All troops may pass through friendly infantry SuGs or artillery in any direction.

But then Rule 9.3H6 (p. 110) foreshadows some exceptions:

Quote"[The following rules] contain exceptions to 5.2 above."

Followed by rule 9.3H6.3 (p. 111):

QuoteA routing UG causes KaB tests on the UG passed through and are then immediately removed.

Finally, back in the section on routs and pursuits we have 9.7B7 (p. 166):

QuoteAny friendly SuGs passed through by routing TuGs are broken and removed...

Getting out my decoder ring, here's what I get:

• A routing TuG passing through a friendly TuG causes a KaB test and then is immediately removed. (as per 9.3H6.3)
• A routing TuG passing through a friendly SuG causes it to be immediately removed. The TuG is then removed as well. (9.7B7 for destroying SuG, 6.3H6.3 for removing TuG.)
• I think flexible mounted in skirmish form suffer a KaB test instead of being destroyed, but I can't find anything on p. 186 about this.
• A routing mounted SuG causes a KaB test on anything it contacts and is then immediately removed. (9.3H6.3 is exception to 9.3H5.2 in the case of routing through infantry SuGs)
• A routing infantry SuG passes through all without affecting them. Think of them as a battlefield neutrino. (9.3H6.3 is not an exception to 9.3H5.1)

High marks, or back to remedial rules reading?

Flexible count as SK for movement and flank marches if in SK formation + for combat but they remain TUGs so yes a KAB

That decoder ring is something you need to hold onto! Does it work for all rule sets? Maybe for income tax forms?