All -
First, my only point for this question was that usually, we want/need specific information and we google or Ctrl-F to find specific answers to our questions. If that is the only way you digest Doctrine (ARs, ADPs, ADRPs, FMs, etc), then you will miss these little tidbits of arcane passages and you will not learn as much as you could if you actually read doctrine.
I want to encourage everyone to just read a chapter a week from some doctrine and encourage your Soldiers to do so as well. In fact, not a bad idea to assign a different chapter to each Soldier in your section and then have them give you an EXSUM/Brief on it.
So, on to the answer...................
Technically - Fiction.
The regulation is very clear and absolutely ridiculous. As SGT O'Neill stated, Cdr's "may" authorize shoes and socks.
Now, I would hope, that no Cmd Tm was so legalistic that they would actually publish a policy letter authorzing shoes and socks with the IPFU, but who knows.
Just another reason that we have needed an update to the AR 670-1 for a longgggggggggggg time.
b. Commanders may authorize wear of commercial running shoes with calf-length or ankle-length, plain white socks
(no logos). If worn, ankle-length socks must cover the entire ankle bone. Shoes must accommodate all five toes in one
compartment. Those shoes that feature five separate, individual compartments for the toes, detract from a professional
military image and are prohibited for wear with the IPFU or when conducting physical training in a military formation.
While running shoes are not listed as a component of the IPFU, neither are socks! Boots aren't mentioned at all in relation to the IPFU. Therefore, wearing the IPFU without having or assuming the commander's approval for authorized accessories would mean being barefoot.
Wearing bare feet with the IPFU would not present a neat and soldierly appearance. Therefore, I have general military authority to wear socks and running shoes.