Re: Other files than the "reserved files" in META-INF?

Excellent Ė thanks Matt!  I am going to leave it in the META-INF as it helps with compatibility to other specs like ASIC, ODF, etc.


From: <>
Date: Wednesday, October 4, 2023 at 10:49 PM
To: Leonard Rosenthol <>, <>
Subject: RE: Other files than the "reserved files" in META-INF?

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Hi Leonard,

It doesnít matter how configuration files come to be there. So long as they arenít publication resources and donít collide with the reserved files, theyíre valid in the META-INF directory.

I would just put the file in the root unless youíre expecting to group multiple files. Iíll hazard a guess that the likelihood of a future naming collision with the spec is pretty low.


From: Leonard Rosenthol <>
Sent: Wednesday, October 4, 2023 9:08 PM
Subject: Other files than the "reserved files" in META-INF?

Context: I am finishing up support for EPUB for C2PA and the logical place to put the Content Credentials (aka C2PA Manifest Store) is in META-INF.

Reading over the 3.3 spec, it is clear in 4.2.2 that the publication itself canít put additional files inside META-INF.  However, it is not clear (either there or in 4.2.6) if there is any restriction on a processing system can place files there that are not referenced.

So any problem with my putting our `content_credentials.c2pa` file in there?   If there is, any other recommendations Ė just the root?


Received on Thursday, 5 October 2023 16:29:00 UTC