ISO 639-3: Low German - nds, Mennonites' Plautdietsch - pdt; Middle Low German (including the lingua franca variety of the Hanseatic League) - gml.
The Library of Congress MARC 21 standard - NDS.
ISO-639-2:  nds.
SIL (14th ed. of The Ethnologue): sxn; presently The Ethnologue uses nds.

The Linguascale (classification developed by L’Observatoire Linguistique) uses several codes for the German varieties used in the past in the present territory of Poland:
- 52-ACB-cg (New-Marchian, Pomeranian from the region of Stettin/Szczecin),
- 52-ACB-ch (most of Pomerania and Prussia),
- 52-ACB-cia (the fragment of Prussia most to the east).
Moreover, the language varieties of the German diaspora:
- 52-ACB-hd (Plautdietsch of Mennonites),
- 52-ACB-hpa (the variety from Esprito Santo, Brazil).