Rank insignia on Soviet uniforms

[snopes]

I have a friend who works for Warner Bros., writing production notes for new films. Since most of the information she uses in her writing comes from people on the set, production notes relating to the historical background of a film's setting may or may not be accurate. So, I was intrigued by the following comment from a costume designer in her notes for The Good German:

The [costume] designer's largest challenge, by volume, was assembling period military uniforms for the four occupying armies. "We had them made all over the world and a lot of it doesn't match but that's okay because they didn't match at the time either," she reveals. The Soviet uniforms, in particular, were coming out of a transitional stage in the early 1940s, wherein medals and insignia denoting rank were being gradually restored after years of being banned in an effort to convey equality among the troops -- a concept that, by the 40s, everyone agreed had fostered more inefficiency than morale.

I don't recall having heard that before. Is it true that pre-1940s Soviet miliary uniforms had no rank insignia because they contradicted Communist ideals of equality?

- snopes