Manifest items can identify resources with absolute URLs. So an EPUB can theoretically use local file system resource with file URLs.
Using file URLs in the manifest is not a good practice, but has never been strictly forbidden (as far as I know). I think it's probably often used by mistake rather than intentionally. But there might be legit use cases, like an internal documentation system (as @mattgarrish pointed out in #1374).
Would it be reasonable to say that absolute URLs SHOULD have a special scheme that is not file?
In parallel we can also make it explicit what Reading Systems can/should do with absolute URLs as manifest entries.
Manifest items can identify resources with absolute URLs. So an EPUB can theoretically use local file system resource with
fileURLs.Using
fileURLs in the manifest is not a good practice, but has never been strictly forbidden (as far as I know). I think it's probably often used by mistake rather than intentionally. But there might be legit use cases, like an internal documentation system (as @mattgarrish pointed out in #1374).Would it be reasonable to say that absolute URLs SHOULD have a special scheme that is not
file?In parallel we can also make it explicit what Reading Systems can/should do with absolute URLs as manifest entries.