[78-L] Fractions as take numbers and "BKP"

[Harold Aherne]

In discographic listings for French Brunswick and Polydor recordings of the early 1930s, I notice that take numbers are indicated as fractions. For instance, Marlene Dietrich's 19 July 1933 session in Paris* was composed of matrices 6476 and 6477, each with three takes: a plain (un-numbered) take, a "1/2" and a "3/4". Would I be correct in guessing that plain=1, 1/2=2, and 3/4=3? 
Brunswick/Polydor's Paris recordings also inserted the letters "BKP" after the matrix numbers. Can anyone comment on what they represent?
-HA
*Information taken from "James Arthur Briggs" by Horst P.J. Bergmeier and Rainer E. Lotz, Black Music Research Journal, Volume 30, Number 1, Spring 2010, pages 93-181.