Could you add below Identifying Codes, please?
UDC (in Poland called UKD) https://en.wikipedia.org/wiki/Universal_Decimal_Classification
Polska Bibliografia Narodowa https://pl.wikipedia.org/wiki/Polska_Bibliografia_Narodowa
OCLC is the organisation that maintains the Dewey Decimal Classification. So if a publication references OCLC, this may just be another way of stating the Dewey number, rather than a different code. Can you give some examples please?
UDC has its roots in Dewey but has evolved into a system in its own right with its own coding structure so it seems reasonable to add it here.
Polska Bibliografia Narodowa. Do you want somewhere to list the number prefixed by BN e.g.
BOLEK Franciszek: Arcybiskup Cieplak i nasza
młodzież. — Detroit 1926 s. 30. 19263
— Metody pasterskie katolickiej hierarchji kościelnej w Stanach Zjednoczonych Ameryki Północnej. —
Sharon, Pa. 1934 cm 23,5 x 16 s. 16, nlb. 1.
UDC should definitely be adde here, and I'd like to have this one added as well:
ББК is the USSR analogue but not the copy of UDC. Nowadays it's actively used in Russia, only recently discontinued in Ukraine. Not sure about the other post USSR countries. And still - this is a huge amount of books covered, so I consider it a must have here.
And another one valid for at least Russia and Ukraine: Author's sign.
Russian identifiers are also mentioned in this topic