A poco file extension is related to the Apple Guide an online help and documentation system.
POCO file extension - Apple Guide data
What is poco file? How to open poco files?
File type specification:
The poco file extension is associated with the Apple Guide, a part of Mac OS Classic operating system that allows users to view help guides for apps.
The poco file stores various data used for internal purposes of the Apple Guide.
This poco 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.