An skcard file extension is related to the Borland Sidekick application and used for its card files.
SKCARD file extension - Borland Sidekick contact
What is skcard file? How to open skcard files?
File type specification:
The skcard file extension is associated with the Borland Sidekick, a personal information management software for MS-DOS and Microsoft Windows.
The .skcard file stores database of contacts (also known as a card file).
Borland Sidekick is obsolete product.
This skcard 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.