Probably, you mean " note of Beria from " _ " March, 1940 № 794/Б ":
Experts of a Katyn’s question (for example - N.S.Lebedeva) approves, that this document has been written on March, 3 1940.
She asserts it because in “note of Beria” figures about number of the captured Poles, conterminous are resulted by that is in the other document - precisely dated (and original) “note Soprunenko” from March, 3 1940:
На записке наркома внутренних дел СССР быт проставлены месяц, год, но отсутствовало число. Она была написана на бланке НКВД СССР и имела регистрационный номер. Именно этот номер помог нам датировать с точностью до одного дня - 3 марта - этот документ. См. подробнее: N. Lebidieva. Process podeimovania decyzji katynskiej// Europa nie prowincjonalna. Warszaw-Londyn, 1999. 8. 1155-1174
( Катынь. Март 1940 — сентябрь 2000. Расстрел. Судьбы живых. Эхо Катыни. (Документы). М., “Весь мир”, 2001, с.44 )
Transleting:
On a note of narkom of internal affairs of the USSR were named month, year, but there was no number of day. It has been written on the form of NKVD of the USSR and had registration number. This number has helped us to date to within one day - on March, 3 - this document. See more in detail: N. Lebidieva. Process podeimovania decyzji katynskiej // Europa nie prowincjonalna. Warszaw-Londyn, 1999.8.1155-1174
(Katyn. March 1940 - September 2000. Execution. Destinies alive. Echo of Katyn. (Documents). М., “ All world ”, 2001, with 44)
But! N.S.Lebedeva did not consider that on March, 2, 1940 L.Beria has sent Stalin a note about the Chinese affairs behind number 810/Б.
This note has been published the last year in the collection of documents
" Lubyanka, Stalin and NKVD-NKGB-GUKR “Smersh” 1939-March 1946 " (Publishing house MFD, Moscow, 2006).( “Лубянка, Сталин и НКВД-НКГБ-ГУКР “Смерш” 1939-март 1946” (Издательство МФД, Москва, 2006) .)
This implies, that the document with smaller (794/Б) number has been signed BEFORE March, 2, 1940 - either on March, 1 or on February, 29, 1940.
In the original document signed by Beria on March, 1, 1940 figures from note of Soprunenkoо from March, 3, 1940 in any way could not appear.
Conclusion - " note of Beria from " _ " March, 1940 " - the latest falsification.