Files with nmdsdcid file extension can be found as settings from some, most likely old, MP3 player devices.
NMDSDCID file extension - MP3 player settings
What is nmdsdcid file? How to open nmdsdcid files?
File type specification:
The nmdsdcid file extension is used in some MP3 players to save its settings.
Probably rare file type only used in certain, probably old devices. Sometimes also found on external data storage cards.
This nmdsdcid file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.