TANKS/GUNS SHOOTING THROUGH OTHER TANKS/GUNS

[Peterloo]

We have always played a tank/gun can shoot through 2 other tanks/guns of its own side. - but for  some reason we decided to check the rules - and couldn't find anything on it (I'm sure it as in the old rules)
this immediately raised the question (and eyebrows) - can they?
it states under shooting restrictions guns can fire through foot (not mg)

now foot cannot fire through own foot/guns/trucks on the principle it could do a blue on blue. - does this apply to guns - no fire through own for the same reason ?