WOFF and extended metadata

I'd like to attempt to clarify what I was trying to express in today's meeting. As I said there, I have some nagging concern about it, but I'm not sure there's any proper way to address it. My concern might also be relatively abstract and not compelling to anyone else.

It's essentially a font foundry advocacy position. If nobody else is concerned, I don't need to fixate on it further, but I'd like to air it out here.

These points are understood and not disputed:

- The WOFF extended metadata block is optional.
- A user agent is not required to do anything with metadata if/when it's present.

The question today was: If a font is received by a UA that has invalid XML metadata, should the UA ignore the metadata block, or reject the font?

I think there was agreement that we'd add a requirement that any WOFF generation tool must produce valid XML for the metadata block. This suggests that any WOFF file with invalid XML is not a compliant WOFF file and has been somehow corrupted or tampered with (either in transmission, or whatever).

This optional extended metadata can be a very important part of WOFF for foundries. (It is certainly seen as indispensable in their support for the format.) Some foundries might choose to include what they consider very important information there. For example, they might include customer information that will help them recognize legal web fonts.

Let's say that some future UA has an option which shows all metadata to the user. It receives a WOFF file with invalid metadata and ignores it. The user inspects the WOFF data via the UA and finds nothing there. They might get the impression that the font is not being used legally.

The overarching questions is this: If a foundry chooses to include extended metadata in a WOFF file, shouldn't that be considered an inextricable component of the WOFF? Yes, the creator of the WOFF is not required to put it there, and the UA is not required to do anything with it, but still, should the UA be permitted to accept the font data without its accompanying metadata?

-Christopher

Received on Wednesday, 19 May 2010 20:30:34 UTC