What are the content types and perceived types in registry editor key?

Question

What are the content types and perceived types in an registry editor key? I have been searching and didn't found anything.

Any help would be great!

Answer 1

Content types are just like perceived, but content type requires an file extension name at the end or random text (content type format: e.g. audio/acc), perceived types have just the file type (audio if it's an audio file, text for text files, etc.)